Convert read_mmblob to take struct object_id.
[gitweb.git] / builtin / apply.c
index c770d7d3d9fd923957478667291a77d33935ebe5..df2c95d3f6f225cc570247cab1c300adf8d2cb6a 100644 (file)
 #include "ll-merge.h"
 #include "rerere.h"
 
-/*
- *  --check turns on checking that the working tree matches the
- *    files that are being modified, but doesn't apply the patch
- *  --stat does just a diffstat, and doesn't actually apply
- *  --numstat does numeric diffstat, and doesn't actually apply
- *  --index-info shows the old and new index info for paths if available.
- *  --index updates the cache as well.
- *  --cached updates only the cache without ever touching the working tree.
- */
-static const char *prefix;
-static int prefix_length = -1;
-static int newfd = -1;
-
-static int unidiff_zero;
-static int p_value = 1;
-static int p_value_known;
-static int check_index;
-static int update_index;
-static int cached;
-static int diffstat;
-static int numstat;
-static int summary;
-static int check;
-static int apply = 1;
-static int apply_in_reverse;
-static int apply_with_reject;
-static int apply_verbosely;
-static int allow_overlap;
-static int no_add;
-static int threeway;
-static int unsafe_paths;
-static const char *fake_ancestor;
-static int line_termination = '\n';
-static unsigned int p_context = UINT_MAX;
-static const char * const apply_usage[] = {
-       N_("git apply [<options>] [<patch>...]"),
-       NULL
-};
-
-static enum ws_error_action {
+enum ws_error_action {
        nowarn_ws_error,
        warn_on_ws_error,
        die_on_ws_error,
        correct_ws_error
-} ws_error_action = warn_on_ws_error;
-static int whitespace_error;
-static int squelch_whitespace_errors = 5;
-static int applied_after_fixing_ws;
+};
+
 
-static enum ws_ignore {
+enum ws_ignore {
        ignore_ws_none,
        ignore_ws_change
-} ws_ignore_action = ignore_ws_none;
+};
+
+/*
+ * We need to keep track of how symlinks in the preimage are
+ * manipulated by the patches.  A patch to add a/b/c where a/b
+ * is a symlink should not be allowed to affect the directory
+ * the symlink points at, but if the same patch removes a/b,
+ * it is perfectly fine, as the patch removes a/b to make room
+ * to create a directory a/b so that a/b/c can be created.
+ *
+ * See also "struct string_list symlink_changes" in "struct
+ * apply_state".
+ */
+#define SYMLINK_GOES_AWAY 01
+#define SYMLINK_IN_RESULT 02
 
+struct apply_state {
+       const char *prefix;
+       int prefix_length;
+
+       /* These are lock_file related */
+       struct lock_file *lock_file;
+       int newfd;
+
+       /* These control what gets looked at and modified */
+       int apply; /* this is not a dry-run */
+       int cached; /* apply to the index only */
+       int check; /* preimage must match working tree, don't actually apply */
+       int check_index; /* preimage must match the indexed version */
+       int update_index; /* check_index && apply */
+
+       /* These control cosmetic aspect of the output */
+       int diffstat; /* just show a diffstat, and don't actually apply */
+       int numstat; /* just show a numeric diffstat, and don't actually apply */
+       int summary; /* just report creation, deletion, etc, and don't actually apply */
+
+       /* These boolean parameters control how the apply is done */
+       int allow_overlap;
+       int apply_in_reverse;
+       int apply_with_reject;
+       int apply_verbosely;
+       int no_add;
+       int threeway;
+       int unidiff_zero;
+       int unsafe_paths;
+
+       /* Other non boolean parameters */
+       const char *fake_ancestor;
+       const char *patch_input_file;
+       int line_termination;
+       struct strbuf root;
+       int p_value;
+       int p_value_known;
+       unsigned int p_context;
+
+       /* Exclude and include path parameters */
+       struct string_list limit_by_name;
+       int has_include;
+
+       /* Various "current state" */
+       int linenr; /* current line number */
+       struct string_list symlink_changes; /* we have to track symlinks */
 
-static const char *patch_input_file;
-static struct strbuf root = STRBUF_INIT;
-static int read_stdin = 1;
-static int options;
+       /*
+        * For "diff-stat" like behaviour, we keep track of the biggest change
+        * we've seen, and the longest filename. That allows us to do simple
+        * scaling.
+        */
+       int max_change;
+       int max_len;
 
-static void parse_whitespace_option(const char *option)
+       /*
+        * Records filenames that have been touched, in order to handle
+        * the case where more than one patches touch the same file.
+        */
+       struct string_list fn_table;
+
+       /* These control whitespace errors */
+       enum ws_error_action ws_error_action;
+       enum ws_ignore ws_ignore_action;
+       const char *whitespace_option;
+       int whitespace_error;
+       int squelch_whitespace_errors;
+       int applied_after_fixing_ws;
+};
+
+static const char * const apply_usage[] = {
+       N_("git apply [<options>] [<patch>...]"),
+       NULL
+};
+
+static void parse_whitespace_option(struct apply_state *state, const char *option)
 {
        if (!option) {
-               ws_error_action = warn_on_ws_error;
+               state->ws_error_action = warn_on_ws_error;
                return;
        }
        if (!strcmp(option, "warn")) {
-               ws_error_action = warn_on_ws_error;
+               state->ws_error_action = warn_on_ws_error;
                return;
        }
        if (!strcmp(option, "nowarn")) {
-               ws_error_action = nowarn_ws_error;
+               state->ws_error_action = nowarn_ws_error;
                return;
        }
        if (!strcmp(option, "error")) {
-               ws_error_action = die_on_ws_error;
+               state->ws_error_action = die_on_ws_error;
                return;
        }
        if (!strcmp(option, "error-all")) {
-               ws_error_action = die_on_ws_error;
-               squelch_whitespace_errors = 0;
+               state->ws_error_action = die_on_ws_error;
+               state->squelch_whitespace_errors = 0;
                return;
        }
        if (!strcmp(option, "strip") || !strcmp(option, "fix")) {
-               ws_error_action = correct_ws_error;
+               state->ws_error_action = correct_ws_error;
                return;
        }
        die(_("unrecognized whitespace option '%s'"), option);
 }
 
-static void parse_ignorewhitespace_option(const char *option)
+static void parse_ignorewhitespace_option(struct apply_state *state,
+                                         const char *option)
 {
        if (!option || !strcmp(option, "no") ||
            !strcmp(option, "false") || !strcmp(option, "never") ||
            !strcmp(option, "none")) {
-               ws_ignore_action = ignore_ws_none;
+               state->ws_ignore_action = ignore_ws_none;
                return;
        }
        if (!strcmp(option, "change")) {
-               ws_ignore_action = ignore_ws_change;
+               state->ws_ignore_action = ignore_ws_change;
                return;
        }
        die(_("unrecognized whitespace ignore option '%s'"), option);
 }
 
-static void set_default_whitespace_mode(const char *whitespace_option)
+static void set_default_whitespace_mode(struct apply_state *state)
 {
-       if (!whitespace_option && !apply_default_whitespace)
-               ws_error_action = (apply ? warn_on_ws_error : nowarn_ws_error);
+       if (!state->whitespace_option && !apply_default_whitespace)
+               state->ws_error_action = (state->apply ? warn_on_ws_error : nowarn_ws_error);
 }
 
-/*
- * For "diff-stat" like behaviour, we keep track of the biggest change
- * we've seen, and the longest filename. That allows us to do simple
- * scaling.
- */
-static int max_change, max_len;
-
-/*
- * Various "current state", notably line numbers and what
- * file (and how) we're patching right now.. The "is_xxxx"
- * things are flags, where -1 means "don't know yet".
- */
-static int linenr = 1;
-
 /*
  * This represents one "hunk" from a patch, starting with
  * "@@ -oldpos,oldlines +newpos,newlines @@" marker.  The
@@ -265,13 +294,6 @@ struct image {
        struct line *line;
 };
 
-/*
- * Records filenames that have been touched, in order to handle
- * the case where more than one patches touch the same file.
- */
-
-static struct string_list fn_table;
-
 static uint32_t hash_line(const char *cp, size_t len)
 {
        size_t i;
@@ -469,7 +491,10 @@ static char *squash_slash(char *name)
        return name;
 }
 
-static char *find_name_gnu(const char *line, const char *def, int p_value)
+static char *find_name_gnu(struct apply_state *state,
+                          const char *line,
+                          const char *def,
+                          int p_value)
 {
        struct strbuf name = STRBUF_INIT;
        char *cp;
@@ -493,8 +518,8 @@ static char *find_name_gnu(const char *line, const char *def, int p_value)
        }
 
        strbuf_remove(&name, 0, cp - name.buf);
-       if (root.len)
-               strbuf_insert(&name, 0, root.buf, root.len);
+       if (state->root.len)
+               strbuf_insert(&name, 0, state->root.buf, state->root.len);
        return squash_slash(strbuf_detach(&name, NULL));
 }
 
@@ -657,8 +682,12 @@ static size_t diff_timestamp_len(const char *line, size_t len)
        return line + len - end;
 }
 
-static char *find_name_common(const char *line, const char *def,
-                             int p_value, const char *end, int terminate)
+static char *find_name_common(struct apply_state *state,
+                             const char *line,
+                             const char *def,
+                             int p_value,
+                             const char *end,
+                             int terminate)
 {
        int len;
        const char *start = NULL;
@@ -696,32 +725,39 @@ static char *find_name_common(const char *line, const char *def,
                        return squash_slash(xstrdup(def));
        }
 
-       if (root.len) {
-               char *ret = xstrfmt("%s%.*s", root.buf, len, start);
+       if (state->root.len) {
+               char *ret = xstrfmt("%s%.*s", state->root.buf, len, start);
                return squash_slash(ret);
        }
 
        return squash_slash(xmemdupz(start, len));
 }
 
-static char *find_name(const char *line, char *def, int p_value, int terminate)
+static char *find_name(struct apply_state *state,
+                      const char *line,
+                      char *def,
+                      int p_value,
+                      int terminate)
 {
        if (*line == '"') {
-               char *name = find_name_gnu(line, def, p_value);
+               char *name = find_name_gnu(state, line, def, p_value);
                if (name)
                        return name;
        }
 
-       return find_name_common(line, def, p_value, NULL, terminate);
+       return find_name_common(state, line, def, p_value, NULL, terminate);
 }
 
-static char *find_name_traditional(const char *line, char *def, int p_value)
+static char *find_name_traditional(struct apply_state *state,
+                                  const char *line,
+                                  char *def,
+                                  int p_value)
 {
        size_t len;
        size_t date_len;
 
        if (*line == '"') {
-               char *name = find_name_gnu(line, def, p_value);
+               char *name = find_name_gnu(state, line, def, p_value);
                if (name)
                        return name;
        }
@@ -729,10 +765,10 @@ static char *find_name_traditional(const char *line, char *def, int p_value)
        len = strchrnul(line, '\n') - line;
        date_len = diff_timestamp_len(line, len);
        if (!date_len)
-               return find_name_common(line, def, p_value, NULL, TERM_TAB);
+               return find_name_common(state, line, def, p_value, NULL, TERM_TAB);
        len -= date_len;
 
-       return find_name_common(line, def, p_value, line + len, 0);
+       return find_name_common(state, line, def, p_value, line + len, 0);
 }
 
 static int count_slashes(const char *cp)
@@ -750,30 +786,30 @@ static int count_slashes(const char *cp)
  * Given the string after "--- " or "+++ ", guess the appropriate
  * p_value for the given patch.
  */
-static int guess_p_value(const char *nameline)
+static int guess_p_value(struct apply_state *state, const char *nameline)
 {
        char *name, *cp;
        int val = -1;
 
        if (is_dev_null(nameline))
                return -1;
-       name = find_name_traditional(nameline, NULL, 0);
+       name = find_name_traditional(state, nameline, NULL, 0);
        if (!name)
                return -1;
        cp = strchr(name, '/');
        if (!cp)
                val = 0;
-       else if (prefix) {
+       else if (state->prefix) {
                /*
                 * Does it begin with "a/$our-prefix" and such?  Then this is
                 * very likely to apply to our directory.
                 */
-               if (!strncmp(name, prefix, prefix_length))
-                       val = count_slashes(prefix);
+               if (!strncmp(name, state->prefix, state->prefix_length))
+                       val = count_slashes(state->prefix);
                else {
                        cp++;
-                       if (!strncmp(cp, prefix, prefix_length))
-                               val = count_slashes(prefix) + 1;
+                       if (!strncmp(cp, state->prefix, state->prefix_length))
+                               val = count_slashes(state->prefix) + 1;
                }
        }
        free(name);
@@ -860,36 +896,39 @@ static int has_epoch_timestamp(const char *nameline)
  * files, we can happily check the index for a match, but for creating a
  * new file we should try to match whatever "patch" does. I have no idea.
  */
-static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
+static void parse_traditional_patch(struct apply_state *state,
+                                   const char *first,
+                                   const char *second,
+                                   struct patch *patch)
 {
        char *name;
 
        first += 4;     /* skip "--- " */
        second += 4;    /* skip "+++ " */
-       if (!p_value_known) {
+       if (!state->p_value_known) {
                int p, q;
-               p = guess_p_value(first);
-               q = guess_p_value(second);
+               p = guess_p_value(state, first);
+               q = guess_p_value(state, second);
                if (p < 0) p = q;
                if (0 <= p && p == q) {
-                       p_value = p;
-                       p_value_known = 1;
+                       state->p_value = p;
+                       state->p_value_known = 1;
                }
        }
        if (is_dev_null(first)) {
                patch->is_new = 1;
                patch->is_delete = 0;
-               name = find_name_traditional(second, NULL, p_value);
+               name = find_name_traditional(state, second, NULL, state->p_value);
                patch->new_name = name;
        } else if (is_dev_null(second)) {
                patch->is_new = 0;
                patch->is_delete = 1;
-               name = find_name_traditional(first, NULL, p_value);
+               name = find_name_traditional(state, first, NULL, state->p_value);
                patch->old_name = name;
        } else {
                char *first_name;
-               first_name = find_name_traditional(first, NULL, p_value);
-               name = find_name_traditional(second, first_name, p_value);
+               first_name = find_name_traditional(state, first, NULL, state->p_value);
+               name = find_name_traditional(state, second, first_name, state->p_value);
                free(first_name);
                if (has_epoch_timestamp(first)) {
                        patch->is_new = 1;
@@ -905,10 +944,12 @@ static void parse_traditional_patch(const char *first, const char *second, struc
                }
        }
        if (!name)
-               die(_("unable to find filename in patch at line %d"), linenr);
+               die(_("unable to find filename in patch at line %d"), state->linenr);
 }
 
-static int gitdiff_hdrend(const char *line, struct patch *patch)
+static int gitdiff_hdrend(struct apply_state *state,
+                         const char *line,
+                         struct patch *patch)
 {
        return -1;
 }
@@ -925,107 +966,135 @@ static int gitdiff_hdrend(const char *line, struct patch *patch)
 #define DIFF_OLD_NAME 0
 #define DIFF_NEW_NAME 1
 
-static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, int side)
+static void gitdiff_verify_name(struct apply_state *state,
+                               const char *line,
+                               int isnull,
+                               char **name,
+                               int side)
 {
-       if (!orig_name && !isnull)
-               return find_name(line, NULL, p_value, TERM_TAB);
+       if (!*name && !isnull) {
+               *name = find_name(state, line, NULL, state->p_value, TERM_TAB);
+               return;
+       }
 
-       if (orig_name) {
-               int len = strlen(orig_name);
+       if (*name) {
+               int len = strlen(*name);
                char *another;
                if (isnull)
                        die(_("git apply: bad git-diff - expected /dev/null, got %s on line %d"),
-                           orig_name, linenr);
-               another = find_name(line, NULL, p_value, TERM_TAB);
-               if (!another || memcmp(another, orig_name, len + 1))
+                           *name, state->linenr);
+               another = find_name(state, line, NULL, state->p_value, TERM_TAB);
+               if (!another || memcmp(another, *name, len + 1))
                        die((side == DIFF_NEW_NAME) ?
                            _("git apply: bad git-diff - inconsistent new filename on line %d") :
-                           _("git apply: bad git-diff - inconsistent old filename on line %d"), linenr);
+                           _("git apply: bad git-diff - inconsistent old filename on line %d"), state->linenr);
                free(another);
-               return orig_name;
        } else {
                /* expect "/dev/null" */
                if (memcmp("/dev/null", line, 9) || line[9] != '\n')
-                       die(_("git apply: bad git-diff - expected /dev/null on line %d"), linenr);
-               return NULL;
+                       die(_("git apply: bad git-diff - expected /dev/null on line %d"), state->linenr);
        }
 }
 
-static int gitdiff_oldname(const char *line, struct patch *patch)
+static int gitdiff_oldname(struct apply_state *state,
+                          const char *line,
+                          struct patch *patch)
 {
-       patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name,
-                                             DIFF_OLD_NAME);
+       gitdiff_verify_name(state, line,
+                           patch->is_new, &patch->old_name,
+                           DIFF_OLD_NAME);
        return 0;
 }
 
-static int gitdiff_newname(const char *line, struct patch *patch)
+static int gitdiff_newname(struct apply_state *state,
+                          const char *line,
+                          struct patch *patch)
 {
-       patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name,
-                                             DIFF_NEW_NAME);
+       gitdiff_verify_name(state, line,
+                           patch->is_delete, &patch->new_name,
+                           DIFF_NEW_NAME);
        return 0;
 }
 
-static int gitdiff_oldmode(const char *line, struct patch *patch)
+static int gitdiff_oldmode(struct apply_state *state,
+                          const char *line,
+                          struct patch *patch)
 {
        patch->old_mode = strtoul(line, NULL, 8);
        return 0;
 }
 
-static int gitdiff_newmode(const char *line, struct patch *patch)
+static int gitdiff_newmode(struct apply_state *state,
+                          const char *line,
+                          struct patch *patch)
 {
        patch->new_mode = strtoul(line, NULL, 8);
        return 0;
 }
 
-static int gitdiff_delete(const char *line, struct patch *patch)
+static int gitdiff_delete(struct apply_state *state,
+                         const char *line,
+                         struct patch *patch)
 {
        patch->is_delete = 1;
        free(patch->old_name);
        patch->old_name = xstrdup_or_null(patch->def_name);
-       return gitdiff_oldmode(line, patch);
+       return gitdiff_oldmode(state, line, patch);
 }
 
-static int gitdiff_newfile(const char *line, struct patch *patch)
+static int gitdiff_newfile(struct apply_state *state,
+                          const char *line,
+                          struct patch *patch)
 {
        patch->is_new = 1;
        free(patch->new_name);
        patch->new_name = xstrdup_or_null(patch->def_name);
-       return gitdiff_newmode(line, patch);
+       return gitdiff_newmode(state, line, patch);
 }
 
-static int gitdiff_copysrc(const char *line, struct patch *patch)
+static int gitdiff_copysrc(struct apply_state *state,
+                          const char *line,
+                          struct patch *patch)
 {
        patch->is_copy = 1;
        free(patch->old_name);
-       patch->old_name = find_name(line, NULL, p_value ? p_value - 1 : 0, 0);
+       patch->old_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
        return 0;
 }
 
-static int gitdiff_copydst(const char *line, struct patch *patch)
+static int gitdiff_copydst(struct apply_state *state,
+                          const char *line,
+                          struct patch *patch)
 {
        patch->is_copy = 1;
        free(patch->new_name);
-       patch->new_name = find_name(line, NULL, p_value ? p_value - 1 : 0, 0);
+       patch->new_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
        return 0;
 }
 
-static int gitdiff_renamesrc(const char *line, struct patch *patch)
+static int gitdiff_renamesrc(struct apply_state *state,
+                            const char *line,
+                            struct patch *patch)
 {
        patch->is_rename = 1;
        free(patch->old_name);
-       patch->old_name = find_name(line, NULL, p_value ? p_value - 1 : 0, 0);
+       patch->old_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
        return 0;
 }
 
-static int gitdiff_renamedst(const char *line, struct patch *patch)
+static int gitdiff_renamedst(struct apply_state *state,
+                            const char *line,
+                            struct patch *patch)
 {
        patch->is_rename = 1;
        free(patch->new_name);
-       patch->new_name = find_name(line, NULL, p_value ? p_value - 1 : 0, 0);
+       patch->new_name = find_name(state, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
        return 0;
 }
 
-static int gitdiff_similarity(const char *line, struct patch *patch)
+static int gitdiff_similarity(struct apply_state *state,
+                             const char *line,
+                             struct patch *patch)
 {
        unsigned long val = strtoul(line, NULL, 10);
        if (val <= 100)
@@ -1033,7 +1102,9 @@ static int gitdiff_similarity(const char *line, struct patch *patch)
        return 0;
 }
 
-static int gitdiff_dissimilarity(const char *line, struct patch *patch)
+static int gitdiff_dissimilarity(struct apply_state *state,
+                                const char *line,
+                                struct patch *patch)
 {
        unsigned long val = strtoul(line, NULL, 10);
        if (val <= 100)
@@ -1041,7 +1112,9 @@ static int gitdiff_dissimilarity(const char *line, struct patch *patch)
        return 0;
 }
 
-static int gitdiff_index(const char *line, struct patch *patch)
+static int gitdiff_index(struct apply_state *state,
+                        const char *line,
+                        struct patch *patch)
 {
        /*
         * index line is N hexadecimal, "..", N hexadecimal,
@@ -1078,7 +1151,9 @@ static int gitdiff_index(const char *line, struct patch *patch)
  * This is normal for a diff that doesn't change anything: we'll fall through
  * into the next diff. Tell the parser to break out.
  */
-static int gitdiff_unrecognized(const char *line, struct patch *patch)
+static int gitdiff_unrecognized(struct apply_state *state,
+                               const char *line,
+                               struct patch *patch)
 {
        return -1;
 }
@@ -1087,15 +1162,17 @@ static int gitdiff_unrecognized(const char *line, struct patch *patch)
  * Skip p_value leading components from "line"; as we do not accept
  * absolute paths, return NULL in that case.
  */
-static const char *skip_tree_prefix(const char *line, int llen)
+static const char *skip_tree_prefix(struct apply_state *state,
+                                   const char *line,
+                                   int llen)
 {
        int nslash;
        int i;
 
-       if (!p_value)
+       if (!state->p_value)
                return (llen && line[0] == '/') ? NULL : line;
 
-       nslash = p_value;
+       nslash = state->p_value;
        for (i = 0; i < llen; i++) {
                int ch = line[i];
                if (ch == '/' && --nslash <= 0)
@@ -1112,7 +1189,9 @@ static const char *skip_tree_prefix(const char *line, int llen)
  * creation or deletion of an empty file.  In any of these cases,
  * both sides are the same name under a/ and b/ respectively.
  */
-static char *git_header_name(const char *line, int llen)
+static char *git_header_name(struct apply_state *state,
+                            const char *line,
+                            int llen)
 {
        const char *name;
        const char *second = NULL;
@@ -1130,7 +1209,7 @@ static char *git_header_name(const char *line, int llen)
                        goto free_and_fail1;
 
                /* strip the a/b prefix including trailing slash */
-               cp = skip_tree_prefix(first.buf, first.len);
+               cp = skip_tree_prefix(state, first.buf, first.len);
                if (!cp)
                        goto free_and_fail1;
                strbuf_remove(&first, 0, cp - first.buf);
@@ -1147,7 +1226,7 @@ static char *git_header_name(const char *line, int llen)
                if (*second == '"') {
                        if (unquote_c_style(&sp, second, NULL))
                                goto free_and_fail1;
-                       cp = skip_tree_prefix(sp.buf, sp.len);
+                       cp = skip_tree_prefix(state, sp.buf, sp.len);
                        if (!cp)
                                goto free_and_fail1;
                        /* They must match, otherwise ignore */
@@ -1158,7 +1237,7 @@ static char *git_header_name(const char *line, int llen)
                }
 
                /* unquoted second */
-               cp = skip_tree_prefix(second, line + llen - second);
+               cp = skip_tree_prefix(state, second, line + llen - second);
                if (!cp)
                        goto free_and_fail1;
                if (line + llen - cp != first.len ||
@@ -1173,7 +1252,7 @@ static char *git_header_name(const char *line, int llen)
        }
 
        /* unquoted first name */
-       name = skip_tree_prefix(line, llen);
+       name = skip_tree_prefix(state, line, llen);
        if (!name)
                return NULL;
 
@@ -1189,7 +1268,7 @@ static char *git_header_name(const char *line, int llen)
                        if (unquote_c_style(&sp, second, NULL))
                                goto free_and_fail2;
 
-                       np = skip_tree_prefix(sp.buf, sp.len);
+                       np = skip_tree_prefix(state, sp.buf, sp.len);
                        if (!np)
                                goto free_and_fail2;
 
@@ -1233,7 +1312,7 @@ static char *git_header_name(const char *line, int llen)
                         */
                        if (!name[len + 1])
                                return NULL; /* no postimage name */
-                       second = skip_tree_prefix(name + len + 1,
+                       second = skip_tree_prefix(state, name + len + 1,
                                                  line_len - (len + 1));
                        if (!second)
                                return NULL;
@@ -1249,7 +1328,11 @@ static char *git_header_name(const char *line, int llen)
 }
 
 /* Verify that we recognize the lines following a git header */
-static int parse_git_header(const char *line, int len, unsigned int size, struct patch *patch)
+static int parse_git_header(struct apply_state *state,
+                           const char *line,
+                           int len,
+                           unsigned int size,
+                           struct patch *patch)
 {
        unsigned long offset;
 
@@ -1263,20 +1346,20 @@ static int parse_git_header(const char *line, int len, unsigned int size, struct
         * or removing or adding empty files), so we get
         * the default name from the header.
         */
-       patch->def_name = git_header_name(line, len);
-       if (patch->def_name && root.len) {
-               char *s = xstrfmt("%s%s", root.buf, patch->def_name);
+       patch->def_name = git_header_name(state, line, len);
+       if (patch->def_name && state->root.len) {
+               char *s = xstrfmt("%s%s", state->root.buf, patch->def_name);
                free(patch->def_name);
                patch->def_name = s;
        }
 
        line += len;
        size -= len;
-       linenr++;
-       for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
+       state->linenr++;
+       for (offset = len ; size > 0 ; offset += len, size -= len, line += len, state->linenr++) {
                static const struct opentry {
                        const char *str;
-                       int (*fn)(const char *, struct patch *);
+                       int (*fn)(struct apply_state *, const char *, struct patch *);
                } optable[] = {
                        { "@@ -", gitdiff_hdrend },
                        { "--- ", gitdiff_oldname },
@@ -1306,7 +1389,7 @@ static int parse_git_header(const char *line, int len, unsigned int size, struct
                        int oplen = strlen(p->str);
                        if (len < oplen || memcmp(p->str, line, oplen))
                                continue;
-                       if (p->fn(line + oplen, patch) < 0)
+                       if (p->fn(state, line + oplen, patch) < 0)
                                return offset;
                        break;
                }
@@ -1431,7 +1514,11 @@ static int parse_fragment_header(const char *line, int len, struct fragment *fra
        return offset;
 }
 
-static int find_header(const char *line, unsigned long size, int *hdrsize, struct patch *patch)
+static int find_header(struct apply_state *state,
+                      const char *line,
+                      unsigned long size,
+                      int *hdrsize,
+                      struct patch *patch)
 {
        unsigned long offset, len;
 
@@ -1440,7 +1527,7 @@ static int find_header(const char *line, unsigned long size, int *hdrsize, struc
        patch->is_new = patch->is_delete = -1;
        patch->old_mode = patch->new_mode = 0;
        patch->old_name = patch->new_name = NULL;
-       for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
+       for (offset = 0; size > 0; offset += len, size -= len, line += len, state->linenr++) {
                unsigned long nextlen;
 
                len = linelen(line, size);
@@ -1461,7 +1548,7 @@ static int find_header(const char *line, unsigned long size, int *hdrsize, struc
                        if (parse_fragment_header(line, len, &dummy) < 0)
                                continue;
                        die(_("patch fragment without header at line %d: %.*s"),
-                           linenr, (int)len-1, line);
+                           state->linenr, (int)len-1, line);
                }
 
                if (size < len + 6)
@@ -1472,7 +1559,7 @@ static int find_header(const char *line, unsigned long size, int *hdrsize, struc
                 * or mode change, so we handle that specially
                 */
                if (!memcmp("diff --git ", line, 11)) {
-                       int git_hdr_len = parse_git_header(line, len, size, patch);
+                       int git_hdr_len = parse_git_header(state, line, len, size, patch);
                        if (git_hdr_len <= len)
                                continue;
                        if (!patch->old_name && !patch->new_name) {
@@ -1481,14 +1568,14 @@ static int find_header(const char *line, unsigned long size, int *hdrsize, struc
                                               "%d leading pathname component (line %d)",
                                               "git diff header lacks filename information when removing "
                                               "%d leading pathname components (line %d)",
-                                              p_value),
-                                           p_value, linenr);
+                                              state->p_value),
+                                           state->p_value, state->linenr);
                                patch->old_name = xstrdup(patch->def_name);
                                patch->new_name = xstrdup(patch->def_name);
                        }
                        if (!patch->is_delete && !patch->new_name)
                                die("git diff header lacks filename information "
-                                   "(line %d)", linenr);
+                                   "(line %d)", state->linenr);
                        patch->is_toplevel_relative = 1;
                        *hdrsize = git_hdr_len;
                        return offset;
@@ -1508,37 +1595,44 @@ static int find_header(const char *line, unsigned long size, int *hdrsize, struc
                        continue;
 
                /* Ok, we'll consider it a patch */
-               parse_traditional_patch(line, line+len, patch);
+               parse_traditional_patch(state, line, line+len, patch);
                *hdrsize = len + nextlen;
-               linenr += 2;
+               state->linenr += 2;
                return offset;
        }
        return -1;
 }
 
-static void record_ws_error(unsigned result, const char *line, int len, int linenr)
+static void record_ws_error(struct apply_state *state,
+                           unsigned result,
+                           const char *line,
+                           int len,
+                           int linenr)
 {
        char *err;
 
        if (!result)
                return;
 
-       whitespace_error++;
-       if (squelch_whitespace_errors &&
-           squelch_whitespace_errors < whitespace_error)
+       state->whitespace_error++;
+       if (state->squelch_whitespace_errors &&
+           state->squelch_whitespace_errors < state->whitespace_error)
                return;
 
        err = whitespace_error_string(result);
        fprintf(stderr, "%s:%d: %s.\n%.*s\n",
-               patch_input_file, linenr, err, len, line);
+               state->patch_input_file, linenr, err, len, line);
        free(err);
 }
 
-static void check_whitespace(const char *line, int len, unsigned ws_rule)
+static void check_whitespace(struct apply_state *state,
+                            const char *line,
+                            int len,
+                            unsigned ws_rule)
 {
        unsigned result = ws_check(line + 1, len - 1, ws_rule);
 
-       record_ws_error(result, line + 1, len - 2, linenr);
+       record_ws_error(state, result, line + 1, len - 2, state->linenr);
 }
 
 /*
@@ -1547,8 +1641,11 @@ static void check_whitespace(const char *line, int len, unsigned ws_rule)
  * between a "---" that is part of a patch, and a "---" that starts
  * the next patch is to look at the line counts..
  */
-static int parse_fragment(const char *line, unsigned long size,
-                         struct patch *patch, struct fragment *fragment)
+static int parse_fragment(struct apply_state *state,
+                         const char *line,
+                         unsigned long size,
+                         struct patch *patch,
+                         struct fragment *fragment)
 {
        int added, deleted;
        int len = linelen(line, size), offset;
@@ -1568,11 +1665,11 @@ static int parse_fragment(const char *line, unsigned long size,
        /* Parse the thing.. */
        line += len;
        size -= len;
-       linenr++;
+       state->linenr++;
        added = deleted = 0;
        for (offset = len;
             0 < size;
-            offset += len, size -= len, line += len, linenr++) {
+            offset += len, size -= len, line += len, state->linenr++) {
                if (!oldlines && !newlines)
                        break;
                len = linelen(line, size);
@@ -1588,22 +1685,22 @@ static int parse_fragment(const char *line, unsigned long size,
                        if (!deleted && !added)
                                leading++;
                        trailing++;
-                       if (!apply_in_reverse &&
-                           ws_error_action == correct_ws_error)
-                               check_whitespace(line, len, patch->ws_rule);
+                       if (!state->apply_in_reverse &&
+                           state->ws_error_action == correct_ws_error)
+                               check_whitespace(state, line, len, patch->ws_rule);
                        break;
                case '-':
-                       if (apply_in_reverse &&
-                           ws_error_action != nowarn_ws_error)
-                               check_whitespace(line, len, patch->ws_rule);
+                       if (state->apply_in_reverse &&
+                           state->ws_error_action != nowarn_ws_error)
+                               check_whitespace(state, line, len, patch->ws_rule);
                        deleted++;
                        oldlines--;
                        trailing = 0;
                        break;
                case '+':
-                       if (!apply_in_reverse &&
-                           ws_error_action != nowarn_ws_error)
-                               check_whitespace(line, len, patch->ws_rule);
+                       if (!state->apply_in_reverse &&
+                           state->ws_error_action != nowarn_ws_error)
+                               check_whitespace(state, line, len, patch->ws_rule);
                        added++;
                        newlines--;
                        trailing = 0;
@@ -1657,7 +1754,10 @@ static int parse_fragment(const char *line, unsigned long size,
  * The (fragment->patch, fragment->size) pair points into the memory given
  * by the caller, not a copy, when we return.
  */
-static int parse_single_patch(const char *line, unsigned long size, struct patch *patch)
+static int parse_single_patch(struct apply_state *state,
+                             const char *line,
+                             unsigned long size,
+                             struct patch *patch)
 {
        unsigned long offset = 0;
        unsigned long oldlines = 0, newlines = 0, context = 0;
@@ -1668,10 +1768,10 @@ static int parse_single_patch(const char *line, unsigned long size, struct patch
                int len;
 
                fragment = xcalloc(1, sizeof(*fragment));
-               fragment->linenr = linenr;
-               len = parse_fragment(line, size, patch, fragment);
+               fragment->linenr = state->linenr;
+               len = parse_fragment(state, line, size, patch, fragment);
                if (len <= 0)
-                       die(_("corrupt patch at line %d"), linenr);
+                       die(_("corrupt patch at line %d"), state->linenr);
                fragment->patch = line;
                fragment->size = len;
                oldlines += fragment->oldlines;
@@ -1757,7 +1857,8 @@ static char *inflate_it(const void *data, unsigned long size,
  * points at an allocated memory that the caller must free, so
  * it is marked as "->free_patch = 1".
  */
-static struct fragment *parse_binary_hunk(char **buf_p,
+static struct fragment *parse_binary_hunk(struct apply_state *state,
+                                         char **buf_p,
                                          unsigned long *sz_p,
                                          int *status_p,
                                          int *used_p)
@@ -1799,13 +1900,13 @@ static struct fragment *parse_binary_hunk(char **buf_p,
        else
                return NULL;
 
-       linenr++;
+       state->linenr++;
        buffer += llen;
        while (1) {
                int byte_length, max_byte_length, newsize;
                llen = linelen(buffer, size);
                used += llen;
-               linenr++;
+               state->linenr++;
                if (llen == 1) {
                        /* consume the blank line */
                        buffer++;
@@ -1859,7 +1960,7 @@ static struct fragment *parse_binary_hunk(char **buf_p,
        free(data);
        *status_p = -1;
        error(_("corrupt binary patch at line %d: %.*s"),
-             linenr-1, llen-1, buffer);
+             state->linenr-1, llen-1, buffer);
        return NULL;
 }
 
@@ -1868,7 +1969,10 @@ static struct fragment *parse_binary_hunk(char **buf_p,
  *   -1 in case of error,
  *   the length of the parsed binary patch otherwise
  */
-static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
+static int parse_binary(struct apply_state *state,
+                       char *buffer,
+                       unsigned long size,
+                       struct patch *patch)
 {
        /*
         * We have read "GIT binary patch\n"; what follows is a line
@@ -1889,15 +1993,15 @@ static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
        int status;
        int used, used_1;
 
-       forward = parse_binary_hunk(&buffer, &size, &status, &used);
+       forward = parse_binary_hunk(state, &buffer, &size, &status, &used);
        if (!forward && !status)
                /* there has to be one hunk (forward hunk) */
-               return error(_("unrecognized binary patch at line %d"), linenr-1);
+               return error(_("unrecognized binary patch at line %d"), state->linenr-1);
        if (status)
                /* otherwise we already gave an error message */
                return status;
 
-       reverse = parse_binary_hunk(&buffer, &size, &status, &used_1);
+       reverse = parse_binary_hunk(state, &buffer, &size, &status, &used_1);
        if (reverse)
                used += used_1;
        else if (status) {
@@ -1915,53 +2019,53 @@ static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
        return used;
 }
 
-static void prefix_one(char **name)
+static void prefix_one(struct apply_state *state, char **name)
 {
        char *old_name = *name;
        if (!old_name)
                return;
-       *name = xstrdup(prefix_filename(prefix, prefix_length, *name));
+       *name = xstrdup(prefix_filename(state->prefix, state->prefix_length, *name));
        free(old_name);
 }
 
-static void prefix_patch(struct patch *p)
+static void prefix_patch(struct apply_state *state, struct patch *p)
 {
-       if (!prefix || p->is_toplevel_relative)
+       if (!state->prefix || p->is_toplevel_relative)
                return;
-       prefix_one(&p->new_name);
-       prefix_one(&p->old_name);
+       prefix_one(state, &p->new_name);
+       prefix_one(state, &p->old_name);
 }
 
 /*
  * include/exclude
  */
 
-static struct string_list limit_by_name;
-static int has_include;
-static void add_name_limit(const char *name, int exclude)
+static void add_name_limit(struct apply_state *state,
+                          const char *name,
+                          int exclude)
 {
        struct string_list_item *it;
 
-       it = string_list_append(&limit_by_name, name);
+       it = string_list_append(&state->limit_by_name, name);
        it->util = exclude ? NULL : (void *) 1;
 }
 
-static int use_patch(struct patch *p)
+static int use_patch(struct apply_state *state, struct patch *p)
 {
        const char *pathname = p->new_name ? p->new_name : p->old_name;
        int i;
 
        /* Paths outside are not touched regardless of "--include" */
-       if (0 < prefix_length) {
+       if (0 < state->prefix_length) {
                int pathlen = strlen(pathname);
-               if (pathlen <= prefix_length ||
-                   memcmp(prefix, pathname, prefix_length))
+               if (pathlen <= state->prefix_length ||
+                   memcmp(state->prefix, pathname, state->prefix_length))
                        return 0;
        }
 
        /* See if it matches any of exclude/include rule */
-       for (i = 0; i < limit_by_name.nr; i++) {
-               struct string_list_item *it = &limit_by_name.items[i];
+       for (i = 0; i < state->limit_by_name.nr; i++) {
+               struct string_list_item *it = &state->limit_by_name.items[i];
                if (!wildmatch(it->string, pathname, 0, NULL))
                        return (it->util != NULL);
        }
@@ -1971,7 +2075,7 @@ static int use_patch(struct patch *p)
         * not used.  Otherwise, we saw bunch of exclude rules (or none)
         * and such a path is used.
         */
-       return !has_include;
+       return !state->has_include;
 }
 
 
@@ -1982,25 +2086,27 @@ static int use_patch(struct patch *p)
  * Return the number of bytes consumed, so that the caller can call us
  * again for the next patch.
  */
-static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
+static int parse_chunk(struct apply_state *state, char *buffer, unsigned long size, struct patch *patch)
 {
        int hdrsize, patchsize;
-       int offset = find_header(buffer, size, &hdrsize, patch);
+       int offset = find_header(state, buffer, size, &hdrsize, patch);
 
        if (offset < 0)
                return offset;
 
-       prefix_patch(patch);
+       prefix_patch(state, patch);
 
-       if (!use_patch(patch))
+       if (!use_patch(state, patch))
                patch->ws_rule = 0;
        else
                patch->ws_rule = whitespace_rule(patch->new_name
                                                 ? patch->new_name
                                                 : patch->old_name);
 
-       patchsize = parse_single_patch(buffer + offset + hdrsize,
-                                      size - offset - hdrsize, patch);
+       patchsize = parse_single_patch(state,
+                                      buffer + offset + hdrsize,
+                                      size - offset - hdrsize,
+                                      patch);
 
        if (!patchsize) {
                static const char git_binary[] = "GIT binary patch\n";
@@ -2010,8 +2116,8 @@ static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
                if (llen == sizeof(git_binary) - 1 &&
                    !memcmp(git_binary, buffer + hd, llen)) {
                        int used;
-                       linenr++;
-                       used = parse_binary(buffer + hd + llen,
+                       state->linenr++;
+                       used = parse_binary(state, buffer + hd + llen,
                                            size - hd - llen, patch);
                        if (used < 0)
                                return -1;
@@ -2031,7 +2137,7 @@ static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
                                int len = strlen(binhdr[i]);
                                if (len < size - hd &&
                                    !memcmp(binhdr[i], buffer + hd, len)) {
-                                       linenr++;
+                                       state->linenr++;
                                        patch->is_binary = 1;
                                        patchsize = llen;
                                        break;
@@ -2043,9 +2149,9 @@ static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
                 * without metadata change.  A binary patch appears
                 * empty to us here.
                 */
-               if ((apply || check) &&
+               if ((state->apply || state->check) &&
                    (!patch->is_binary && !metadata_changes(patch)))
-                       die(_("patch with only garbage at line %d"), linenr);
+                       die(_("patch with only garbage at line %d"), state->linenr);
        }
 
        return offset + hdrsize + patchsize;
@@ -2083,7 +2189,7 @@ static const char pluses[] =
 static const char minuses[]=
 "----------------------------------------------------------------------";
 
-static void show_stats(struct patch *patch)
+static void show_stats(struct apply_state *state, struct patch *patch)
 {
        struct strbuf qname = STRBUF_INIT;
        char *cp = patch->new_name ? patch->new_name : patch->old_name;
@@ -2094,7 +2200,7 @@ static void show_stats(struct patch *patch)
        /*
         * "scale" the filename
         */
-       max = max_len;
+       max = state->max_len;
        if (max > 50)
                max = 50;
 
@@ -2117,13 +2223,13 @@ static void show_stats(struct patch *patch)
        /*
         * scale the add/delete
         */
-       max = max + max_change > 70 ? 70 - max : max_change;
+       max = max + state->max_change > 70 ? 70 - max : state->max_change;
        add = patch->lines_added;
        del = patch->lines_deleted;
 
-       if (max_change > 0) {
-               int total = ((add + del) * max + max_change / 2) / max_change;
-               add = (add * max + max_change / 2) / max_change;
+       if (state->max_change > 0) {
+               int total = ((add + del) * max + state->max_change / 2) / state->max_change;
+               add = (add * max + state->max_change / 2) / state->max_change;
                del = total - add;
        }
        printf("%5d %.*s%.*s\n", patch->lines_added + patch->lines_deleted,
@@ -2194,17 +2300,17 @@ static void update_pre_post_images(struct image *preimage,
        fixed = preimage->buf;
 
        for (i = reduced = ctx = 0; i < postimage->nr; i++) {
-               size_t len = postimage->line[i].len;
+               size_t l_len = postimage->line[i].len;
                if (!(postimage->line[i].flag & LINE_COMMON)) {
                        /* an added line -- no counterparts in preimage */
-                       memmove(new, old, len);
-                       old += len;
-                       new += len;
+                       memmove(new, old, l_len);
+                       old += l_len;
+                       new += l_len;
                        continue;
                }
 
                /* a common context -- skip it in the original postimage */
-               old += len;
+               old += l_len;
 
                /* and find the corresponding one in the fixed preimage */
                while (ctx < preimage->nr &&
@@ -2223,11 +2329,11 @@ static void update_pre_post_images(struct image *preimage,
                }
 
                /* and copy it in, while fixing the line length */
-               len = preimage->line[ctx].len;
-               memcpy(new, fixed, len);
-               new += len;
-               fixed += len;
-               postimage->line[i].len = len;
+               l_len = preimage->line[ctx].len;
+               memcpy(new, fixed, l_len);
+               new += l_len;
+               fixed += l_len;
+               postimage->line[i].len = l_len;
                ctx++;
        }
 
@@ -2242,7 +2348,76 @@ static void update_pre_post_images(struct image *preimage,
        postimage->nr -= reduced;
 }
 
-static int match_fragment(struct image *img,
+static int line_by_line_fuzzy_match(struct image *img,
+                                   struct image *preimage,
+                                   struct image *postimage,
+                                   unsigned long try,
+                                   int try_lno,
+                                   int preimage_limit)
+{
+       int i;
+       size_t imgoff = 0;
+       size_t preoff = 0;
+       size_t postlen = postimage->len;
+       size_t extra_chars;
+       char *buf;
+       char *preimage_eof;
+       char *preimage_end;
+       struct strbuf fixed;
+       char *fixed_buf;
+       size_t fixed_len;
+
+       for (i = 0; i < preimage_limit; i++) {
+               size_t prelen = preimage->line[i].len;
+               size_t imglen = img->line[try_lno+i].len;
+
+               if (!fuzzy_matchlines(img->buf + try + imgoff, imglen,
+                                     preimage->buf + preoff, prelen))
+                       return 0;
+               if (preimage->line[i].flag & LINE_COMMON)
+                       postlen += imglen - prelen;
+               imgoff += imglen;
+               preoff += prelen;
+       }
+
+       /*
+        * Ok, the preimage matches with whitespace fuzz.
+        *
+        * imgoff now holds the true length of the target that
+        * matches the preimage before the end of the file.
+        *
+        * Count the number of characters in the preimage that fall
+        * beyond the end of the file and make sure that all of them
+        * are whitespace characters. (This can only happen if
+        * we are removing blank lines at the end of the file.)
+        */
+       buf = preimage_eof = preimage->buf + preoff;
+       for ( ; i < preimage->nr; i++)
+               preoff += preimage->line[i].len;
+       preimage_end = preimage->buf + preoff;
+       for ( ; buf < preimage_end; buf++)
+               if (!isspace(*buf))
+                       return 0;
+
+       /*
+        * Update the preimage and the common postimage context
+        * lines to use the same whitespace as the target.
+        * If whitespace is missing in the target (i.e.
+        * if the preimage extends beyond the end of the file),
+        * use the whitespace from the preimage.
+        */
+       extra_chars = preimage_end - preimage_eof;
+       strbuf_init(&fixed, imgoff + extra_chars);
+       strbuf_add(&fixed, img->buf + try, imgoff);
+       strbuf_add(&fixed, preimage_eof, extra_chars);
+       fixed_buf = strbuf_detach(&fixed, &fixed_len);
+       update_pre_post_images(preimage, postimage,
+                              fixed_buf, fixed_len, postlen);
+       return 1;
+}
+
+static int match_fragment(struct apply_state *state,
+                         struct image *img,
                          struct image *preimage,
                          struct image *postimage,
                          unsigned long try,
@@ -2263,7 +2438,7 @@ static int match_fragment(struct image *img,
                preimage_limit = preimage->nr;
                if (match_end && (preimage->nr + try_lno != img->nr))
                        return 0;
-       } else if (ws_error_action == correct_ws_error &&
+       } else if (state->ws_error_action == correct_ws_error &&
                   (ws_rule & WS_BLANK_AT_EOF)) {
                /*
                 * This hunk extends beyond the end of img, and we are
@@ -2331,63 +2506,11 @@ static int match_fragment(struct image *img,
         * fuzzy matching. We collect all the line length information because
         * we need it to adjust whitespace if we match.
         */
-       if (ws_ignore_action == ignore_ws_change) {
-               size_t imgoff = 0;
-               size_t preoff = 0;
-               size_t postlen = postimage->len;
-               size_t extra_chars;
-               char *preimage_eof;
-               char *preimage_end;
-               for (i = 0; i < preimage_limit; i++) {
-                       size_t prelen = preimage->line[i].len;
-                       size_t imglen = img->line[try_lno+i].len;
-
-                       if (!fuzzy_matchlines(img->buf + try + imgoff, imglen,
-                                             preimage->buf + preoff, prelen))
-                               return 0;
-                       if (preimage->line[i].flag & LINE_COMMON)
-                               postlen += imglen - prelen;
-                       imgoff += imglen;
-                       preoff += prelen;
-               }
+       if (state->ws_ignore_action == ignore_ws_change)
+               return line_by_line_fuzzy_match(img, preimage, postimage,
+                                               try, try_lno, preimage_limit);
 
-               /*
-                * Ok, the preimage matches with whitespace fuzz.
-                *
-                * imgoff now holds the true length of the target that
-                * matches the preimage before the end of the file.
-                *
-                * Count the number of characters in the preimage that fall
-                * beyond the end of the file and make sure that all of them
-                * are whitespace characters. (This can only happen if
-                * we are removing blank lines at the end of the file.)
-                */
-               buf = preimage_eof = preimage->buf + preoff;
-               for ( ; i < preimage->nr; i++)
-                       preoff += preimage->line[i].len;
-               preimage_end = preimage->buf + preoff;
-               for ( ; buf < preimage_end; buf++)
-                       if (!isspace(*buf))
-                               return 0;
-
-               /*
-                * Update the preimage and the common postimage context
-                * lines to use the same whitespace as the target.
-                * If whitespace is missing in the target (i.e.
-                * if the preimage extends beyond the end of the file),
-                * use the whitespace from the preimage.
-                */
-               extra_chars = preimage_end - preimage_eof;
-               strbuf_init(&fixed, imgoff + extra_chars);
-               strbuf_add(&fixed, img->buf + try, imgoff);
-               strbuf_add(&fixed, preimage_eof, extra_chars);
-               fixed_buf = strbuf_detach(&fixed, &fixed_len);
-               update_pre_post_images(preimage, postimage,
-                               fixed_buf, fixed_len, postlen);
-               return 1;
-       }
-
-       if (ws_error_action != correct_ws_error)
+       if (state->ws_error_action != correct_ws_error)
                return 0;
 
        /*
@@ -2499,7 +2622,8 @@ static int match_fragment(struct image *img,
        return 0;
 }
 
-static int find_pos(struct image *img,
+static int find_pos(struct apply_state *state,
+                   struct image *img,
                    struct image *preimage,
                    struct image *postimage,
                    int line,
@@ -2543,7 +2667,7 @@ static int find_pos(struct image *img,
        try_lno = line;
 
        for (i = 0; ; i++) {
-               if (match_fragment(img, preimage, postimage,
+               if (match_fragment(state, img, preimage, postimage,
                                   try, try_lno, ws_rule,
                                   match_beginning, match_end))
                        return try_lno;
@@ -2594,7 +2718,8 @@ static void remove_last_line(struct image *img)
  * apply at applied_pos (counts in line numbers) in "img".
  * Update "img" to remove "preimage" and replace it with "postimage".
  */
-static void update_image(struct image *img,
+static void update_image(struct apply_state *state,
+                        struct image *img,
                         int applied_pos,
                         struct image *preimage,
                         struct image *postimage)
@@ -2659,7 +2784,7 @@ static void update_image(struct image *img,
        memcpy(img->line + applied_pos,
               postimage->line,
               postimage->nr * sizeof(*img->line));
-       if (!allow_overlap)
+       if (!state->allow_overlap)
                for (i = 0; i < postimage->nr; i++)
                        img->line[applied_pos + i].flag |= LINE_PATCHED;
        img->nr = nr;
@@ -2670,7 +2795,8 @@ static void update_image(struct image *img,
  * postimage) for the hunk.  Find lines that match "preimage" in "img" and
  * replace the part of "img" with "postimage" text.
  */
-static int apply_one_fragment(struct image *img, struct fragment *frag,
+static int apply_one_fragment(struct apply_state *state,
+                             struct image *img, struct fragment *frag,
                              int inaccurate_eof, unsigned ws_rule,
                              int nth_fragment)
 {
@@ -2715,7 +2841,7 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
                if (len < size && patch[len] == '\\')
                        plen--;
                first = *patch;
-               if (apply_in_reverse) {
+               if (state->apply_in_reverse) {
                        if (first == '-')
                                first = '+';
                        else if (first == '+')
@@ -2748,17 +2874,17 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
                /* Fall-through for ' ' */
                case '+':
                        /* --no-add does not add new lines */
-                       if (first == '+' && no_add)
+                       if (first == '+' && state->no_add)
                                break;
 
                        start = newlines.len;
                        if (first != '+' ||
-                           !whitespace_error ||
-                           ws_error_action != correct_ws_error) {
+                           !state->whitespace_error ||
+                           state->ws_error_action != correct_ws_error) {
                                strbuf_add(&newlines, patch + 1, plen);
                        }
                        else {
-                               ws_fix_copy(&newlines, patch + 1, plen, ws_rule, &applied_after_fixing_ws);
+                               ws_fix_copy(&newlines, patch + 1, plen, ws_rule, &state->applied_after_fixing_ws);
                        }
                        add_line_info(&postimage, newlines.buf + start, newlines.len - start,
                                      (first == '+' ? 0 : LINE_COMMON));
@@ -2771,7 +2897,7 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
                        /* Ignore it, we already handled it */
                        break;
                default:
-                       if (apply_verbosely)
+                       if (state->apply_verbosely)
                                error(_("invalid start of line: '%c'"), first);
                        applied_pos = -1;
                        goto out;
@@ -2812,7 +2938,7 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
         * without leading context must match at the beginning.
         */
        match_beginning = (!frag->oldpos ||
-                          (frag->oldpos == 1 && !unidiff_zero));
+                          (frag->oldpos == 1 && !state->unidiff_zero));
 
        /*
         * A hunk without trailing lines must match at the end.
@@ -2820,7 +2946,7 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
         * from the lack of trailing lines if the patch was generated
         * with unidiff without any context.
         */
-       match_end = !unidiff_zero && !trailing;
+       match_end = !state->unidiff_zero && !trailing;
 
        pos = frag->newpos ? (frag->newpos - 1) : 0;
        preimage.buf = oldlines;
@@ -2832,14 +2958,14 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
 
        for (;;) {
 
-               applied_pos = find_pos(img, &preimage, &postimage, pos,
+               applied_pos = find_pos(state, img, &preimage, &postimage, pos,
                                       ws_rule, match_beginning, match_end);
 
                if (applied_pos >= 0)
                        break;
 
                /* Am I at my context limits? */
-               if ((leading <= p_context) && (trailing <= p_context))
+               if ((leading <= state->p_context) && (trailing <= state->p_context))
                        break;
                if (match_beginning || match_end) {
                        match_beginning = match_end = 0;
@@ -2868,10 +2994,10 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
                if (new_blank_lines_at_end &&
                    preimage.nr + applied_pos >= img->nr &&
                    (ws_rule & WS_BLANK_AT_EOF) &&
-                   ws_error_action != nowarn_ws_error) {
-                       record_ws_error(WS_BLANK_AT_EOF, "+", 1,
+                   state->ws_error_action != nowarn_ws_error) {
+                       record_ws_error(state, WS_BLANK_AT_EOF, "+", 1,
                                        found_new_blank_lines_at_end);
-                       if (ws_error_action == correct_ws_error) {
+                       if (state->ws_error_action == correct_ws_error) {
                                while (new_blank_lines_at_end--)
                                        remove_last_line(&postimage);
                        }
@@ -2882,13 +3008,13 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
                         * apply_patch->check_patch_list->check_patch->
                         * apply_data->apply_fragments->apply_one_fragment
                         */
-                       if (ws_error_action == die_on_ws_error)
-                               apply = 0;
+                       if (state->ws_error_action == die_on_ws_error)
+                               state->apply = 0;
                }
 
-               if (apply_verbosely && applied_pos != pos) {
+               if (state->apply_verbosely && applied_pos != pos) {
                        int offset = applied_pos - pos;
-                       if (apply_in_reverse)
+                       if (state->apply_in_reverse)
                                offset = 0 - offset;
                        fprintf_ln(stderr,
                                   Q_("Hunk #%d succeeded at %d (offset %d line).",
@@ -2906,9 +3032,9 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
                        fprintf_ln(stderr, _("Context reduced to (%ld/%ld)"
                                             " to apply fragment at %d"),
                                   leading, trailing, applied_pos+1);
-               update_image(img, applied_pos, &preimage, &postimage);
+               update_image(state, img, applied_pos, &preimage, &postimage);
        } else {
-               if (apply_verbosely)
+               if (state->apply_verbosely)
                        error(_("while searching for:\n%.*s"),
                              (int)(old - oldlines), oldlines);
        }
@@ -2922,7 +3048,9 @@ static int apply_one_fragment(struct image *img, struct fragment *frag,
        return (applied_pos < 0);
 }
 
-static int apply_binary_fragment(struct image *img, struct patch *patch)
+static int apply_binary_fragment(struct apply_state *state,
+                                struct image *img,
+                                struct patch *patch)
 {
        struct fragment *fragment = patch->fragments;
        unsigned long len;
@@ -2935,7 +3063,7 @@ static int apply_binary_fragment(struct image *img, struct patch *patch)
                             patch->old_name);
 
        /* Binary patch is irreversible without the optional second hunk */
-       if (apply_in_reverse) {
+       if (state->apply_in_reverse) {
                if (!fragment->next)
                        return error("cannot reverse-apply a binary patch "
                                     "without the reverse hunk to '%s'",
@@ -2968,19 +3096,21 @@ static int apply_binary_fragment(struct image *img, struct patch *patch)
  * but the preimage prepared by the caller in "img" is freed here
  * or in the helper function apply_binary_fragment() this calls.
  */
-static int apply_binary(struct image *img, struct patch *patch)
+static int apply_binary(struct apply_state *state,
+                       struct image *img,
+                       struct patch *patch)
 {
        const char *name = patch->old_name ? patch->old_name : patch->new_name;
-       unsigned char sha1[20];
+       struct object_id oid;
 
        /*
         * For safety, we require patch index line to contain
         * full 40-byte textual SHA1 for old and new, at least for now.
         */
-       if (strlen(patch->old_sha1_prefix) != 40 ||
-           strlen(patch->new_sha1_prefix) != 40 ||
-           get_sha1_hex(patch->old_sha1_prefix, sha1) ||
-           get_sha1_hex(patch->new_sha1_prefix, sha1))
+       if (strlen(patch->old_sha1_prefix) != GIT_SHA1_HEXSZ ||
+           strlen(patch->new_sha1_prefix) != GIT_SHA1_HEXSZ ||
+           get_oid_hex(patch->old_sha1_prefix, &oid) ||
+           get_oid_hex(patch->new_sha1_prefix, &oid))
                return error("cannot apply binary patch to '%s' "
                             "without full index line", name);
 
@@ -2989,12 +3119,12 @@ static int apply_binary(struct image *img, struct patch *patch)
                 * See if the old one matches what the patch
                 * applies to.
                 */
-               hash_sha1_file(img->buf, img->len, blob_type, sha1);
-               if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
+               hash_sha1_file(img->buf, img->len, blob_type, oid.hash);
+               if (strcmp(oid_to_hex(&oid), patch->old_sha1_prefix))
                        return error("the patch applies to '%s' (%s), "
                                     "which does not match the "
                                     "current contents.",
-                                    name, sha1_to_hex(sha1));
+                                    name, oid_to_hex(&oid));
        }
        else {
                /* Otherwise, the old one must be empty. */
@@ -3003,19 +3133,19 @@ static int apply_binary(struct image *img, struct patch *patch)
                                     "'%s' but it is not empty", name);
        }
 
-       get_sha1_hex(patch->new_sha1_prefix, sha1);
-       if (is_null_sha1(sha1)) {
+       get_oid_hex(patch->new_sha1_prefix, &oid);
+       if (is_null_oid(&oid)) {
                clear_image(img);
                return 0; /* deletion patch */
        }
 
-       if (has_sha1_file(sha1)) {
+       if (has_sha1_file(oid.hash)) {
                /* We already have the postimage */
                enum object_type type;
                unsigned long size;
                char *result;
 
-               result = read_sha1_file(sha1, &type, &size);
+               result = read_sha1_file(oid.hash, &type, &size);
                if (!result)
                        return error("the necessary postimage %s for "
                                     "'%s' cannot be read",
@@ -3029,21 +3159,21 @@ static int apply_binary(struct image *img, struct patch *patch)
                 * apply the patch data to it, which is stored
                 * in the patch->fragments->{patch,size}.
                 */
-               if (apply_binary_fragment(img, patch))
+               if (apply_binary_fragment(state, img, patch))
                        return error(_("binary patch does not apply to '%s'"),
                                     name);
 
                /* verify that the result matches */
-               hash_sha1_file(img->buf, img->len, blob_type, sha1);
-               if (strcmp(sha1_to_hex(sha1), patch->new_sha1_prefix))
+               hash_sha1_file(img->buf, img->len, blob_type, oid.hash);
+               if (strcmp(oid_to_hex(&oid), patch->new_sha1_prefix))
                        return error(_("binary patch to '%s' creates incorrect result (expecting %s, got %s)"),
-                               name, patch->new_sha1_prefix, sha1_to_hex(sha1));
+                               name, patch->new_sha1_prefix, oid_to_hex(&oid));
        }
 
        return 0;
 }
 
-static int apply_fragments(struct image *img, struct patch *patch)
+static int apply_fragments(struct apply_state *state, struct image *img, struct patch *patch)
 {
        struct fragment *frag = patch->fragments;
        const char *name = patch->old_name ? patch->old_name : patch->new_name;
@@ -3052,13 +3182,13 @@ static int apply_fragments(struct image *img, struct patch *patch)
        int nth = 0;
 
        if (patch->is_binary)
-               return apply_binary(img, patch);
+               return apply_binary(state, img, patch);
 
        while (frag) {
                nth++;
-               if (apply_one_fragment(img, frag, inaccurate_eof, ws_rule, nth)) {
+               if (apply_one_fragment(state, img, frag, inaccurate_eof, ws_rule, nth)) {
                        error(_("patch failed: %s:%ld"), name, frag->oldpos);
-                       if (!apply_with_reject)
+                       if (!state->apply_with_reject)
                                return -1;
                        frag->rejected = 1;
                }
@@ -3067,17 +3197,17 @@ static int apply_fragments(struct image *img, struct patch *patch)
        return 0;
 }
 
-static int read_blob_object(struct strbuf *buf, const unsigned char *sha1, unsigned mode)
+static int read_blob_object(struct strbuf *buf, const struct object_id *oid, unsigned mode)
 {
        if (S_ISGITLINK(mode)) {
                strbuf_grow(buf, 100);
-               strbuf_addf(buf, "Subproject commit %s\n", sha1_to_hex(sha1));
+               strbuf_addf(buf, "Subproject commit %s\n", oid_to_hex(oid));
        } else {
                enum object_type type;
                unsigned long sz;
                char *result;
 
-               result = read_sha1_file(sha1, &type, &sz);
+               result = read_sha1_file(oid->hash, &type, &sz);
                if (!result)
                        return -1;
                /* XXX read_sha1_file NUL-terminates */
@@ -3090,17 +3220,17 @@ static int read_file_or_gitlink(const struct cache_entry *ce, struct strbuf *buf
 {
        if (!ce)
                return 0;
-       return read_blob_object(buf, ce->sha1, ce->ce_mode);
+       return read_blob_object(buf, &ce->oid, ce->ce_mode);
 }
 
-static struct patch *in_fn_table(const char *name)
+static struct patch *in_fn_table(struct apply_state *state, const char *name)
 {
        struct string_list_item *item;
 
        if (name == NULL)
                return NULL;
 
-       item = string_list_lookup(&fn_table, name);
+       item = string_list_lookup(&state->fn_table, name);
        if (item != NULL)
                return (struct patch *)item->util;
 
@@ -3132,7 +3262,7 @@ static int was_deleted(struct patch *patch)
        return patch == PATH_WAS_DELETED;
 }
 
-static void add_to_fn_table(struct patch *patch)
+static void add_to_fn_table(struct apply_state *state, struct patch *patch)
 {
        struct string_list_item *item;
 
@@ -3142,7 +3272,7 @@ static void add_to_fn_table(struct patch *patch)
         * file creations and copies
         */
        if (patch->new_name != NULL) {
-               item = string_list_insert(&fn_table, patch->new_name);
+               item = string_list_insert(&state->fn_table, patch->new_name);
                item->util = patch;
        }
 
@@ -3151,12 +3281,12 @@ static void add_to_fn_table(struct patch *patch)
         * later chunks shouldn't patch old names
         */
        if ((patch->new_name == NULL) || (patch->is_rename)) {
-               item = string_list_insert(&fn_table, patch->old_name);
+               item = string_list_insert(&state->fn_table, patch->old_name);
                item->util = PATH_WAS_DELETED;
        }
 }
 
-static void prepare_fn_table(struct patch *patch)
+static void prepare_fn_table(struct apply_state *state, struct patch *patch)
 {
        /*
         * store information about incoming file deletion
@@ -3164,7 +3294,7 @@ static void prepare_fn_table(struct patch *patch)
        while (patch) {
                if ((patch->new_name == NULL) || (patch->is_rename)) {
                        struct string_list_item *item;
-                       item = string_list_insert(&fn_table, patch->old_name);
+                       item = string_list_insert(&state->fn_table, patch->old_name);
                        item->util = PATH_TO_BE_DELETED;
                }
                patch = patch->next;
@@ -3185,7 +3315,9 @@ static int checkout_target(struct index_state *istate,
        return 0;
 }
 
-static struct patch *previous_patch(struct patch *patch, int *gone)
+static struct patch *previous_patch(struct apply_state *state,
+                                   struct patch *patch,
+                                   int *gone)
 {
        struct patch *previous;
 
@@ -3193,7 +3325,7 @@ static struct patch *previous_patch(struct patch *patch, int *gone)
        if (patch->is_copy || patch->is_rename)
                return NULL; /* "git" patches do not depend on the order */
 
-       previous = in_fn_table(patch->old_name);
+       previous = in_fn_table(state, patch->old_name);
        if (!previous)
                return NULL;
 
@@ -3218,15 +3350,16 @@ static int verify_index_match(const struct cache_entry *ce, struct stat *st)
 
 #define SUBMODULE_PATCH_WITHOUT_INDEX 1
 
-static int load_patch_target(struct strbuf *buf,
+static int load_patch_target(struct apply_state *state,
+                            struct strbuf *buf,
                             const struct cache_entry *ce,
                             struct stat *st,
                             const char *name,
                             unsigned expected_mode)
 {
-       if (cached || check_index) {
+       if (state->cached || state->check_index) {
                if (read_file_or_gitlink(ce, buf))
-                       return error(_("read of %s failed"), name);
+                       return error(_("failed to read %s"), name);
        } else if (name) {
                if (S_ISGITLINK(expected_mode)) {
                        if (ce)
@@ -3237,7 +3370,7 @@ static int load_patch_target(struct strbuf *buf,
                        return error(_("reading from '%s' beyond a symbolic link"), name);
                } else {
                        if (read_old_data(st, name, buf))
-                               return error(_("read of %s failed"), name);
+                               return error(_("failed to read %s"), name);
                }
        }
        return 0;
@@ -3250,7 +3383,8 @@ static int load_patch_target(struct strbuf *buf,
  * applying a non-git patch that incrementally updates the tree,
  * we read from the result of a previous diff.
  */
-static int load_preimage(struct image *image,
+static int load_preimage(struct apply_state *state,
+                        struct image *image,
                         struct patch *patch, struct stat *st,
                         const struct cache_entry *ce)
 {
@@ -3260,7 +3394,7 @@ static int load_preimage(struct image *image,
        struct patch *previous;
        int status;
 
-       previous = previous_patch(patch, &status);
+       previous = previous_patch(state, patch, &status);
        if (status)
                return error(_("path %s has been renamed/deleted"),
                             patch->old_name);
@@ -3268,7 +3402,7 @@ static int load_preimage(struct image *image,
                /* We have a patched copy in memory; use that. */
                strbuf_add(&buf, previous->result, previous->resultsize);
        } else {
-               status = load_patch_target(&buf, ce, st,
+               status = load_patch_target(state, &buf, ce, st,
                                           patch->old_name, patch->old_mode);
                if (status < 0)
                        return status;
@@ -3282,7 +3416,7 @@ static int load_preimage(struct image *image,
                        free_fragment_list(patch->fragments);
                        patch->fragments = NULL;
                } else if (status) {
-                       return error(_("read of %s failed"), patch->old_name);
+                       return error(_("failed to read %s"), patch->old_name);
                }
        }
 
@@ -3293,9 +3427,9 @@ static int load_preimage(struct image *image,
 
 static int three_way_merge(struct image *image,
                           char *path,
-                          const unsigned char *base,
-                          const unsigned char *ours,
-                          const unsigned char *theirs)
+                          const struct object_id *base,
+                          const struct object_id *ours,
+                          const struct object_id *theirs)
 {
        mmfile_t base_file, our_file, their_file;
        mmbuffer_t result = { NULL };
@@ -3327,7 +3461,9 @@ static int three_way_merge(struct image *image,
  * the current contents of the new_name.  In no cases other than that
  * this function will be called.
  */
-static int load_current(struct image *image, struct patch *patch)
+static int load_current(struct apply_state *state,
+                       struct image *image,
+                       struct patch *patch)
 {
        struct strbuf buf = STRBUF_INIT;
        int status, pos;
@@ -3354,7 +3490,7 @@ static int load_current(struct image *image, struct patch *patch)
        if (verify_index_match(ce, &st))
                return error(_("%s: does not match index"), name);
 
-       status = load_patch_target(&buf, ce, &st, name, mode);
+       status = load_patch_target(state, &buf, ce, &st, name, mode);
        if (status < 0)
                return status;
        else if (status)
@@ -3364,10 +3500,13 @@ static int load_current(struct image *image, struct patch *patch)
        return 0;
 }
 
-static int try_threeway(struct image *image, struct patch *patch,
-                       struct stat *st, const struct cache_entry *ce)
+static int try_threeway(struct apply_state *state,
+                       struct image *image,
+                       struct patch *patch,
+                       struct stat *st,
+                       const struct cache_entry *ce)
 {
-       unsigned char pre_sha1[20], post_sha1[20], our_sha1[20];
+       struct object_id pre_oid, post_oid, our_oid;
        struct strbuf buf = STRBUF_INIT;
        size_t len;
        int status;
@@ -3381,9 +3520,9 @@ static int try_threeway(struct image *image, struct patch *patch,
 
        /* Preimage the patch was prepared for */
        if (patch->is_new)
-               write_sha1_file("", 0, blob_type, pre_sha1);
-       else if (get_sha1(patch->old_sha1_prefix, pre_sha1) ||
-                read_blob_object(&buf, pre_sha1, patch->old_mode))
+               write_sha1_file("", 0, blob_type, pre_oid.hash);
+       else if (get_sha1(patch->old_sha1_prefix, pre_oid.hash) ||
+                read_blob_object(&buf, &pre_oid, patch->old_mode))
                return error("repository lacks the necessary blob to fall back on 3-way merge.");
 
        fprintf(stderr, "Falling back to three-way merge...\n");
@@ -3391,30 +3530,30 @@ static int try_threeway(struct image *image, struct patch *patch,
        img = strbuf_detach(&buf, &len);
        prepare_image(&tmp_image, img, len, 1);
        /* Apply the patch to get the post image */
-       if (apply_fragments(&tmp_image, patch) < 0) {
+       if (apply_fragments(state, &tmp_image, patch) < 0) {
                clear_image(&tmp_image);
                return -1;
        }
        /* post_sha1[] is theirs */
-       write_sha1_file(tmp_image.buf, tmp_image.len, blob_type, post_sha1);
+       write_sha1_file(tmp_image.buf, tmp_image.len, blob_type, post_oid.hash);
        clear_image(&tmp_image);
 
        /* our_sha1[] is ours */
        if (patch->is_new) {
-               if (load_current(&tmp_image, patch))
+               if (load_current(state, &tmp_image, patch))
                        return error("cannot read the current contents of '%s'",
                                     patch->new_name);
        } else {
-               if (load_preimage(&tmp_image, patch, st, ce))
+               if (load_preimage(state, &tmp_image, patch, st, ce))
                        return error("cannot read the current contents of '%s'",
                                     patch->old_name);
        }
-       write_sha1_file(tmp_image.buf, tmp_image.len, blob_type, our_sha1);
+       write_sha1_file(tmp_image.buf, tmp_image.len, blob_type, our_oid.hash);
        clear_image(&tmp_image);
 
        /* in-core three-way merge between post and our using pre as base */
        status = three_way_merge(image, patch->new_name,
-                                pre_sha1, our_sha1, post_sha1);
+                                &pre_oid, &our_oid, &post_oid);
        if (status < 0) {
                fprintf(stderr, "Failed to fall back on three-way merge...\n");
                return status;
@@ -3425,9 +3564,9 @@ static int try_threeway(struct image *image, struct patch *patch,
                if (patch->is_new)
                        oidclr(&patch->threeway_stage[0]);
                else
-                       hashcpy(patch->threeway_stage[0].hash, pre_sha1);
-               hashcpy(patch->threeway_stage[1].hash, our_sha1);
-               hashcpy(patch->threeway_stage[2].hash, post_sha1);
+                       oidcpy(&patch->threeway_stage[0], &pre_oid);
+               oidcpy(&patch->threeway_stage[1], &our_oid);
+               oidcpy(&patch->threeway_stage[2], &post_oid);
                fprintf(stderr, "Applied patch to '%s' with conflicts.\n", patch->new_name);
        } else {
                fprintf(stderr, "Applied patch to '%s' cleanly.\n", patch->new_name);
@@ -3435,22 +3574,23 @@ static int try_threeway(struct image *image, struct patch *patch,
        return 0;
 }
 
-static int apply_data(struct patch *patch, struct stat *st, const struct cache_entry *ce)
+static int apply_data(struct apply_state *state, struct patch *patch,
+                     struct stat *st, const struct cache_entry *ce)
 {
        struct image image;
 
-       if (load_preimage(&image, patch, st, ce) < 0)
+       if (load_preimage(state, &image, patch, st, ce) < 0)
                return -1;
 
        if (patch->direct_to_threeway ||
-           apply_fragments(&image, patch) < 0) {
+           apply_fragments(state, &image, patch) < 0) {
                /* Note: with --reject, apply_fragments() returns 0 */
-               if (!threeway || try_threeway(&image, patch, st, ce) < 0)
+               if (!state->threeway || try_threeway(state, &image, patch, st, ce) < 0)
                        return -1;
        }
        patch->result = image.buf;
        patch->resultsize = image.len;
-       add_to_fn_table(patch);
+       add_to_fn_table(state, patch);
        free(image.line_allocated);
 
        if (0 < patch->is_delete && patch->resultsize)
@@ -3470,7 +3610,10 @@ static int apply_data(struct patch *patch, struct stat *st, const struct cache_e
  * check_patch() separately makes sure (and errors out otherwise) that
  * the path the patch creates does not exist in the current tree.
  */
-static int check_preimage(struct patch *patch, struct cache_entry **ce, struct stat *st)
+static int check_preimage(struct apply_state *state,
+                         struct patch *patch,
+                         struct cache_entry **ce,
+                         struct stat *st)
 {
        const char *old_name = patch->old_name;
        struct patch *previous = NULL;
@@ -3481,19 +3624,19 @@ static int check_preimage(struct patch *patch, struct cache_entry **ce, struct s
                return 0;
 
        assert(patch->is_new <= 0);
-       previous = previous_patch(patch, &status);
+       previous = previous_patch(state, patch, &status);
 
        if (status)
                return error(_("path %s has been renamed/deleted"), old_name);
        if (previous) {
                st_mode = previous->new_mode;
-       } else if (!cached) {
+       } else if (!state->cached) {
                stat_ret = lstat(old_name, st);
                if (stat_ret && errno != ENOENT)
                        return error(_("%s: %s"), old_name, strerror(errno));
        }
 
-       if (check_index && !previous) {
+       if (state->check_index && !previous) {
                int pos = cache_name_pos(old_name, strlen(old_name));
                if (pos < 0) {
                        if (patch->is_new < 0)
@@ -3505,9 +3648,9 @@ static int check_preimage(struct patch *patch, struct cache_entry **ce, struct s
                        if (checkout_target(&the_index, *ce, st))
                                return -1;
                }
-               if (!cached && verify_index_match(*ce, st))
+               if (!state->cached && verify_index_match(*ce, st))
                        return error(_("%s: does not match index"), old_name);
-               if (cached)
+               if (state->cached)
                        st_mode = (*ce)->ce_mode;
        } else if (stat_ret < 0) {
                if (patch->is_new < 0)
@@ -3515,7 +3658,7 @@ static int check_preimage(struct patch *patch, struct cache_entry **ce, struct s
                return error(_("%s: %s"), old_name, strerror(errno));
        }
 
-       if (!cached && !previous)
+       if (!state->cached && !previous)
                st_mode = ce_mode_from_stat(*ce, st->st_mode);
 
        if (patch->is_new < 0)
@@ -3543,15 +3686,17 @@ static int check_preimage(struct patch *patch, struct cache_entry **ce, struct s
 #define EXISTS_IN_INDEX 1
 #define EXISTS_IN_WORKTREE 2
 
-static int check_to_create(const char *new_name, int ok_if_exists)
+static int check_to_create(struct apply_state *state,
+                          const char *new_name,
+                          int ok_if_exists)
 {
        struct stat nst;
 
-       if (check_index &&
+       if (state->check_index &&
            cache_name_pos(new_name, strlen(new_name)) >= 0 &&
            !ok_if_exists)
                return EXISTS_IN_INDEX;
-       if (cached)
+       if (state->cached)
                return 0;
 
        if (!lstat(new_name, &nst)) {
@@ -3574,56 +3719,46 @@ static int check_to_create(const char *new_name, int ok_if_exists)
        return 0;
 }
 
-/*
- * We need to keep track of how symlinks in the preimage are
- * manipulated by the patches.  A patch to add a/b/c where a/b
- * is a symlink should not be allowed to affect the directory
- * the symlink points at, but if the same patch removes a/b,
- * it is perfectly fine, as the patch removes a/b to make room
- * to create a directory a/b so that a/b/c can be created.
- */
-static struct string_list symlink_changes;
-#define SYMLINK_GOES_AWAY 01
-#define SYMLINK_IN_RESULT 02
-
-static uintptr_t register_symlink_changes(const char *path, uintptr_t what)
+static uintptr_t register_symlink_changes(struct apply_state *state,
+                                         const char *path,
+                                         uintptr_t what)
 {
        struct string_list_item *ent;
 
-       ent = string_list_lookup(&symlink_changes, path);
+       ent = string_list_lookup(&state->symlink_changes, path);
        if (!ent) {
-               ent = string_list_insert(&symlink_changes, path);
+               ent = string_list_insert(&state->symlink_changes, path);
                ent->util = (void *)0;
        }
        ent->util = (void *)(what | ((uintptr_t)ent->util));
        return (uintptr_t)ent->util;
 }
 
-static uintptr_t check_symlink_changes(const char *path)
+static uintptr_t check_symlink_changes(struct apply_state *state, const char *path)
 {
        struct string_list_item *ent;
 
-       ent = string_list_lookup(&symlink_changes, path);
+       ent = string_list_lookup(&state->symlink_changes, path);
        if (!ent)
                return 0;
        return (uintptr_t)ent->util;
 }
 
-static void prepare_symlink_changes(struct patch *patch)
+static void prepare_symlink_changes(struct apply_state *state, struct patch *patch)
 {
        for ( ; patch; patch = patch->next) {
                if ((patch->old_name && S_ISLNK(patch->old_mode)) &&
                    (patch->is_rename || patch->is_delete))
                        /* the symlink at patch->old_name is removed */
-                       register_symlink_changes(patch->old_name, SYMLINK_GOES_AWAY);
+                       register_symlink_changes(state, patch->old_name, SYMLINK_GOES_AWAY);
 
                if (patch->new_name && S_ISLNK(patch->new_mode))
                        /* the symlink at patch->new_name is created or remains */
-                       register_symlink_changes(patch->new_name, SYMLINK_IN_RESULT);
+                       register_symlink_changes(state, patch->new_name, SYMLINK_IN_RESULT);
        }
 }
 
-static int path_is_beyond_symlink_1(struct strbuf *name)
+static int path_is_beyond_symlink_1(struct apply_state *state, struct strbuf *name)
 {
        do {
                unsigned int change;
@@ -3633,7 +3768,7 @@ static int path_is_beyond_symlink_1(struct strbuf *name)
                if (!name->len)
                        break;
                name->buf[name->len] = '\0';
-               change = check_symlink_changes(name->buf);
+               change = check_symlink_changes(state, name->buf);
                if (change & SYMLINK_IN_RESULT)
                        return 1;
                if (change & SYMLINK_GOES_AWAY)
@@ -3644,7 +3779,7 @@ static int path_is_beyond_symlink_1(struct strbuf *name)
                        continue;
 
                /* otherwise, check the preimage */
-               if (check_index) {
+               if (state->check_index) {
                        struct cache_entry *ce;
 
                        ce = cache_file_exists(name->buf, name->len, ignore_case);
@@ -3659,14 +3794,14 @@ static int path_is_beyond_symlink_1(struct strbuf *name)
        return 0;
 }
 
-static int path_is_beyond_symlink(const char *name_)
+static int path_is_beyond_symlink(struct apply_state *state, const char *name_)
 {
        int ret;
        struct strbuf name = STRBUF_INIT;
 
        assert(*name_ != '\0');
        strbuf_addstr(&name, name_);
-       ret = path_is_beyond_symlink_1(&name);
+       ret = path_is_beyond_symlink_1(state, &name);
        strbuf_release(&name);
 
        return ret;
@@ -3693,7 +3828,7 @@ static void die_on_unsafe_path(struct patch *patch)
  * Check and apply the patch in-core; leave the result in patch->result
  * for the caller to write it out to the final destination.
  */
-static int check_patch(struct patch *patch)
+static int check_patch(struct apply_state *state, struct patch *patch)
 {
        struct stat st;
        const char *old_name = patch->old_name;
@@ -3706,7 +3841,7 @@ static int check_patch(struct patch *patch)
 
        patch->rejected = 1; /* we will drop this after we succeed */
 
-       status = check_preimage(patch, &ce, &st);
+       status = check_preimage(state, patch, &ce, &st);
        if (status)
                return status;
        old_name = patch->old_name;
@@ -3725,7 +3860,7 @@ static int check_patch(struct patch *patch)
         * B and rename from A to B is handled the same way by asking
         * was_deleted().
         */
-       if ((tpatch = in_fn_table(new_name)) &&
+       if ((tpatch = in_fn_table(state, new_name)) &&
            (was_deleted(tpatch) || to_be_deleted(tpatch)))
                ok_if_exists = 1;
        else
@@ -3733,9 +3868,9 @@ static int check_patch(struct patch *patch)
 
        if (new_name &&
            ((0 < patch->is_new) || patch->is_rename || patch->is_copy)) {
-               int err = check_to_create(new_name, ok_if_exists);
+               int err = check_to_create(state, new_name, ok_if_exists);
 
-               if (err && threeway) {
+               if (err && state->threeway) {
                        patch->direct_to_threeway = 1;
                } else switch (err) {
                case 0:
@@ -3776,7 +3911,7 @@ static int check_patch(struct patch *patch)
                }
        }
 
-       if (!unsafe_paths)
+       if (!state->unsafe_paths)
                die_on_unsafe_path(patch);
 
        /*
@@ -3788,34 +3923,34 @@ static int check_patch(struct patch *patch)
         * is not deposited to a path that is beyond a symbolic link
         * here.
         */
-       if (!patch->is_delete && path_is_beyond_symlink(patch->new_name))
+       if (!patch->is_delete && path_is_beyond_symlink(state, patch->new_name))
                return error(_("affected file '%s' is beyond a symbolic link"),
                             patch->new_name);
 
-       if (apply_data(patch, &st, ce) < 0)
+       if (apply_data(state, patch, &st, ce) < 0)
                return error(_("%s: patch does not apply"), name);
        patch->rejected = 0;
        return 0;
 }
 
-static int check_patch_list(struct patch *patch)
+static int check_patch_list(struct apply_state *state, struct patch *patch)
 {
        int err = 0;
 
-       prepare_symlink_changes(patch);
-       prepare_fn_table(patch);
+       prepare_symlink_changes(state, patch);
+       prepare_fn_table(state, patch);
        while (patch) {
-               if (apply_verbosely)
+               if (state->apply_verbosely)
                        say_patch_name(stderr,
                                       _("Checking patch %s..."), patch);
-               err |= check_patch(patch);
+               err |= check_patch(state, patch);
                patch = patch->next;
        }
        return err;
 }
 
-/* This function tries to read the sha1 from the current index */
-static int get_current_sha1(const char *path, unsigned char *sha1)
+/* This function tries to read the object ID from the current index */
+static int get_current_oid(const char *path, struct object_id *oid)
 {
        int pos;
 
@@ -3824,11 +3959,11 @@ static int get_current_sha1(const char *path, unsigned char *sha1)
        pos = cache_name_pos(path, strlen(path));
        if (pos < 0)
                return -1;
-       hashcpy(sha1, active_cache[pos]->sha1);
+       oidcpy(oid, &active_cache[pos]->oid);
        return 0;
 }
 
-static int preimage_sha1_in_gitlink_patch(struct patch *p, unsigned char sha1[20])
+static int preimage_oid_in_gitlink_patch(struct patch *p, struct object_id *oid)
 {
        /*
         * A usable gitlink patch has only one fragment (hunk) that looks like:
@@ -3852,14 +3987,14 @@ static int preimage_sha1_in_gitlink_patch(struct patch *p, unsigned char sha1[20
            (preimage = memchr(hunk->patch, '\n', hunk->size)) != NULL &&
            starts_with(++preimage, heading) &&
            /* does it record full SHA-1? */
-           !get_sha1_hex(preimage + sizeof(heading) - 1, sha1) &&
-           preimage[sizeof(heading) + 40 - 1] == '\n' &&
+           !get_oid_hex(preimage + sizeof(heading) - 1, oid) &&
+           preimage[sizeof(heading) + GIT_SHA1_HEXSZ - 1] == '\n' &&
            /* does the abbreviated name on the index line agree with it? */
            starts_with(preimage + sizeof(heading) - 1, p->old_sha1_prefix))
                return 0; /* it all looks fine */
 
        /* we may have full object name on the index line */
-       return get_sha1_hex(p->old_sha1_prefix, sha1);
+       return get_oid_hex(p->old_sha1_prefix, oid);
 }
 
 /* Build an index that contains the just the files needed for a 3way merge */
@@ -3873,7 +4008,7 @@ static void build_fake_ancestor(struct patch *list, const char *filename)
         * worth showing the new sha1 prefix, but until then...
         */
        for (patch = list; patch; patch = patch->next) {
-               unsigned char sha1[20];
+               struct object_id oid;
                struct cache_entry *ce;
                const char *name;
 
@@ -3882,23 +4017,23 @@ static void build_fake_ancestor(struct patch *list, const char *filename)
                        continue;
 
                if (S_ISGITLINK(patch->old_mode)) {
-                       if (!preimage_sha1_in_gitlink_patch(patch, sha1))
+                       if (!preimage_oid_in_gitlink_patch(patch, &oid))
                                ; /* ok, the textual part looks sane */
                        else
                                die("sha1 information is lacking or useless for submodule %s",
                                    name);
-               } else if (!get_sha1_blob(patch->old_sha1_prefix, sha1)) {
+               } else if (!get_sha1_blob(patch->old_sha1_prefix, oid.hash)) {
                        ; /* ok */
                } else if (!patch->lines_added && !patch->lines_deleted) {
                        /* mode-only change: update the current */
-                       if (get_current_sha1(patch->old_name, sha1))
+                       if (get_current_oid(patch->old_name, &oid))
                                die("mode change for %s, which is not "
                                    "in current HEAD", name);
                } else
                        die("sha1 information is lacking or useless "
                            "(%s).", name);
 
-               ce = make_cache_entry(patch->old_mode, sha1, name, 0, 0);
+               ce = make_cache_entry(patch->old_mode, oid.hash, name, 0, 0);
                if (!ce)
                        die(_("make_cache_entry failed for path '%s'"), name);
                if (add_index_entry(&result, ce, ADD_CACHE_OK_TO_ADD))
@@ -3912,7 +4047,7 @@ static void build_fake_ancestor(struct patch *list, const char *filename)
        discard_index(&result);
 }
 
-static void stat_patch_list(struct patch *patch)
+static void stat_patch_list(struct apply_state *state, struct patch *patch)
 {
        int files, adds, dels;
 
@@ -3920,13 +4055,14 @@ static void stat_patch_list(struct patch *patch)
                files++;
                adds += patch->lines_added;
                dels += patch->lines_deleted;
-               show_stats(patch);
+               show_stats(state, patch);
        }
 
        print_stat_summary(stdout, files, adds, dels);
 }
 
-static void numstat_patch_list(struct patch *patch)
+static void numstat_patch_list(struct apply_state *state,
+                              struct patch *patch)
 {
        for ( ; patch; patch = patch->next) {
                const char *name;
@@ -3935,7 +4071,7 @@ static void numstat_patch_list(struct patch *patch)
                        printf("-\t-\t");
                else
                        printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
-               write_name_quoted(name, stdout, line_termination);
+               write_name_quoted(name, stdout, state->line_termination);
        }
 }
 
@@ -4017,49 +4153,53 @@ static void summary_patch_list(struct patch *patch)
        }
 }
 
-static void patch_stats(struct patch *patch)
+static void patch_stats(struct apply_state *state, struct patch *patch)
 {
        int lines = patch->lines_added + patch->lines_deleted;
 
-       if (lines > max_change)
-               max_change = lines;
+       if (lines > state->max_change)
+               state->max_change = lines;
        if (patch->old_name) {
                int len = quote_c_style(patch->old_name, NULL, NULL, 0);
                if (!len)
                        len = strlen(patch->old_name);
-               if (len > max_len)
-                       max_len = len;
+               if (len > state->max_len)
+                       state->max_len = len;
        }
        if (patch->new_name) {
                int len = quote_c_style(patch->new_name, NULL, NULL, 0);
                if (!len)
                        len = strlen(patch->new_name);
-               if (len > max_len)
-                       max_len = len;
+               if (len > state->max_len)
+                       state->max_len = len;
        }
 }
 
-static void remove_file(struct patch *patch, int rmdir_empty)
+static void remove_file(struct apply_state *state, struct patch *patch, int rmdir_empty)
 {
-       if (update_index) {
+       if (state->update_index) {
                if (remove_file_from_cache(patch->old_name) < 0)
                        die(_("unable to remove %s from index"), patch->old_name);
        }
-       if (!cached) {
+       if (!state->cached) {
                if (!remove_or_warn(patch->old_mode, patch->old_name) && rmdir_empty) {
                        remove_path(patch->old_name);
                }
        }
 }
 
-static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
+static void add_index_file(struct apply_state *state,
+                          const char *path,
+                          unsigned mode,
+                          void *buf,
+                          unsigned long size)
 {
        struct stat st;
        struct cache_entry *ce;
        int namelen = strlen(path);
        unsigned ce_size = cache_entry_size(namelen);
 
-       if (!update_index)
+       if (!state->update_index)
                return;
 
        ce = xcalloc(1, ce_size);
@@ -4071,16 +4211,16 @@ static void add_index_file(const char *path, unsigned mode, void *buf, unsigned
                const char *s;
 
                if (!skip_prefix(buf, "Subproject commit ", &s) ||
-                   get_sha1_hex(s, ce->sha1))
+                   get_oid_hex(s, &ce->oid))
                        die(_("corrupt patch for submodule %s"), path);
        } else {
-               if (!cached) {
+               if (!state->cached) {
                        if (lstat(path, &st) < 0)
                                die_errno(_("unable to stat newly created file '%s'"),
                                          path);
                        fill_stat_cache_info(ce, &st);
                }
-               if (write_sha1_file(buf, size, blob_type, ce->sha1) < 0)
+               if (write_sha1_file(buf, size, blob_type, ce->oid.hash) < 0)
                        die(_("unable to create backing store for newly created file %s"), path);
        }
        if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
@@ -4126,9 +4266,13 @@ static int try_create_file(const char *path, unsigned int mode, const char *buf,
  * which is true 99% of the time anyway. If they don't,
  * we create them and try again.
  */
-static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
+static void create_one_file(struct apply_state *state,
+                           char *path,
+                           unsigned mode,
+                           const char *buf,
+                           unsigned long size)
 {
-       if (cached)
+       if (state->cached)
                return;
        if (!try_create_file(path, mode, buf, size))
                return;
@@ -4169,13 +4313,14 @@ static void create_one_file(char *path, unsigned mode, const char *buf, unsigned
        die_errno(_("unable to write file '%s' mode %o"), path, mode);
 }
 
-static void add_conflicted_stages_file(struct patch *patch)
+static void add_conflicted_stages_file(struct apply_state *state,
+                                      struct patch *patch)
 {
        int stage, namelen;
        unsigned ce_size, mode;
        struct cache_entry *ce;
 
-       if (!update_index)
+       if (!state->update_index)
                return;
        namelen = strlen(patch->new_name);
        ce_size = cache_entry_size(namelen);
@@ -4190,13 +4335,13 @@ static void add_conflicted_stages_file(struct patch *patch)
                ce->ce_mode = create_ce_mode(mode);
                ce->ce_flags = create_ce_flags(stage);
                ce->ce_namelen = namelen;
-               hashcpy(ce->sha1, patch->threeway_stage[stage - 1].hash);
+               oidcpy(&ce->oid, &patch->threeway_stage[stage - 1]);
                if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
                        die(_("unable to add cache entry for %s"), patch->new_name);
        }
 }
 
-static void create_file(struct patch *patch)
+static void create_file(struct apply_state *state, struct patch *patch)
 {
        char *path = patch->new_name;
        unsigned mode = patch->new_mode;
@@ -4205,25 +4350,27 @@ static void create_file(struct patch *patch)
 
        if (!mode)
                mode = S_IFREG | 0644;
-       create_one_file(path, mode, buf, size);
+       create_one_file(state, path, mode, buf, size);
 
        if (patch->conflicted_threeway)
-               add_conflicted_stages_file(patch);
+               add_conflicted_stages_file(state, patch);
        else
-               add_index_file(path, mode, buf, size);
+               add_index_file(state, path, mode, buf, size);
 }
 
 /* phase zero is to remove, phase one is to create */
-static void write_out_one_result(struct patch *patch, int phase)
+static void write_out_one_result(struct apply_state *state,
+                                struct patch *patch,
+                                int phase)
 {
        if (patch->is_delete > 0) {
                if (phase == 0)
-                       remove_file(patch, 1);
+                       remove_file(state, patch, 1);
                return;
        }
        if (patch->is_new > 0 || patch->is_copy) {
                if (phase == 1)
-                       create_file(patch);
+                       create_file(state, patch);
                return;
        }
        /*
@@ -4231,12 +4378,12 @@ static void write_out_one_result(struct patch *patch, int phase)
         * thing: remove the old, write the new
         */
        if (phase == 0)
-               remove_file(patch, patch->is_rename);
+               remove_file(state, patch, patch->is_rename);
        if (phase == 1)
-               create_file(patch);
+               create_file(state, patch);
 }
 
-static int write_out_one_reject(struct patch *patch)
+static int write_out_one_reject(struct apply_state *state, struct patch *patch)
 {
        FILE *rej;
        char namebuf[PATH_MAX];
@@ -4251,7 +4398,7 @@ static int write_out_one_reject(struct patch *patch)
        }
 
        if (!cnt) {
-               if (apply_verbosely)
+               if (state->apply_verbosely)
                        say_patch_name(stderr,
                                       _("Applied patch %s cleanly."), patch);
                return 0;
@@ -4307,7 +4454,7 @@ static int write_out_one_reject(struct patch *patch)
        return -1;
 }
 
-static int write_out_results(struct patch *list)
+static int write_out_results(struct apply_state *state, struct patch *list)
 {
        int phase;
        int errs = 0;
@@ -4320,9 +4467,9 @@ static int write_out_results(struct patch *list)
                        if (l->rejected)
                                errs = 1;
                        else {
-                               write_out_one_result(l, phase);
+                               write_out_one_result(state, l, phase);
                                if (phase == 1) {
-                                       if (write_out_one_reject(l))
+                                       if (write_out_one_reject(state, l))
                                                errs = 1;
                                        if (l->conflicted_threeway) {
                                                string_list_append(&cpath, l->new_name);
@@ -4353,14 +4500,17 @@ static struct lock_file lock_file;
 #define INACCURATE_EOF (1<<0)
 #define RECOUNT                (1<<1)
 
-static int apply_patch(int fd, const char *filename, int options)
+static int apply_patch(struct apply_state *state,
+                      int fd,
+                      const char *filename,
+                      int options)
 {
        size_t offset;
        struct strbuf buf = STRBUF_INIT; /* owns the patch text */
        struct patch *list = NULL, **listp = &list;
        int skipped_patch = 0;
 
-       patch_input_file = filename;
+       state->patch_input_file = filename;
        read_patch_file(&buf, fd);
        offset = 0;
        while (offset < buf.len) {
@@ -4370,20 +4520,20 @@ static int apply_patch(int fd, const char *filename, int options)
                patch = xcalloc(1, sizeof(*patch));
                patch->inaccurate_eof = !!(options & INACCURATE_EOF);
                patch->recount =  !!(options & RECOUNT);
-               nr = parse_chunk(buf.buf + offset, buf.len - offset, patch);
+               nr = parse_chunk(state, buf.buf + offset, buf.len - offset, patch);
                if (nr < 0) {
                        free_patch(patch);
                        break;
                }
-               if (apply_in_reverse)
+               if (state->apply_in_reverse)
                        reverse_patches(patch);
-               if (use_patch(patch)) {
-                       patch_stats(patch);
+               if (use_patch(state, patch)) {
+                       patch_stats(state, patch);
                        *listp = patch;
                        listp = &patch->next;
                }
                else {
-                       if (apply_verbosely)
+                       if (state->apply_verbosely)
                                say_patch_name(stderr, _("Skipped patch '%s'."), patch);
                        free_patch(patch);
                        skipped_patch++;
@@ -4394,45 +4544,45 @@ static int apply_patch(int fd, const char *filename, int options)
        if (!list && !skipped_patch)
                die(_("unrecognized input"));
 
-       if (whitespace_error && (ws_error_action == die_on_ws_error))
-               apply = 0;
+       if (state->whitespace_error && (state->ws_error_action == die_on_ws_error))
+               state->apply = 0;
 
-       update_index = check_index && apply;
-       if (update_index && newfd < 0)
-               newfd = hold_locked_index(&lock_file, 1);
+       state->update_index = state->check_index && state->apply;
+       if (state->update_index && state->newfd < 0)
+               state->newfd = hold_locked_index(state->lock_file, 1);
 
-       if (check_index) {
+       if (state->check_index) {
                if (read_cache() < 0)
                        die(_("unable to read index file"));
        }
 
-       if ((check || apply) &&
-           check_patch_list(list) < 0 &&
-           !apply_with_reject)
+       if ((state->check || state->apply) &&
+           check_patch_list(state, list) < 0 &&
+           !state->apply_with_reject)
                exit(1);
 
-       if (apply && write_out_results(list)) {
-               if (apply_with_reject)
+       if (state->apply && write_out_results(state, list)) {
+               if (state->apply_with_reject)
                        exit(1);
                /* with --3way, we still need to write the index out */
                return 1;
        }
 
-       if (fake_ancestor)
-               build_fake_ancestor(list, fake_ancestor);
+       if (state->fake_ancestor)
+               build_fake_ancestor(list, state->fake_ancestor);
 
-       if (diffstat)
-               stat_patch_list(list);
+       if (state->diffstat)
+               stat_patch_list(state, list);
 
-       if (numstat)
-               numstat_patch_list(list);
+       if (state->numstat)
+               numstat_patch_list(state, list);
 
-       if (summary)
+       if (state->summary)
                summary_patch_list(list);
 
        free_patch_list(list);
        strbuf_release(&buf);
-       string_list_clear(&fn_table, 0);
+       string_list_clear(&state->fn_table, 0);
        return 0;
 }
 
@@ -4446,220 +4596,284 @@ static void git_apply_config(void)
 static int option_parse_exclude(const struct option *opt,
                                const char *arg, int unset)
 {
-       add_name_limit(arg, 1);
+       struct apply_state *state = opt->value;
+       add_name_limit(state, arg, 1);
        return 0;
 }
 
 static int option_parse_include(const struct option *opt,
                                const char *arg, int unset)
 {
-       add_name_limit(arg, 0);
-       has_include = 1;
+       struct apply_state *state = opt->value;
+       add_name_limit(state, arg, 0);
+       state->has_include = 1;
        return 0;
 }
 
 static int option_parse_p(const struct option *opt,
-                         const char *arg, int unset)
+                         const char *arg,
+                         int unset)
 {
-       p_value = atoi(arg);
-       p_value_known = 1;
+       struct apply_state *state = opt->value;
+       state->p_value = atoi(arg);
+       state->p_value_known = 1;
        return 0;
 }
 
 static int option_parse_space_change(const struct option *opt,
-                         const char *arg, int unset)
+                                    const char *arg, int unset)
 {
+       struct apply_state *state = opt->value;
        if (unset)
-               ws_ignore_action = ignore_ws_none;
+               state->ws_ignore_action = ignore_ws_none;
        else
-               ws_ignore_action = ignore_ws_change;
+               state->ws_ignore_action = ignore_ws_change;
        return 0;
 }
 
 static int option_parse_whitespace(const struct option *opt,
                                   const char *arg, int unset)
 {
-       const char **whitespace_option = opt->value;
-
-       *whitespace_option = arg;
-       parse_whitespace_option(arg);
+       struct apply_state *state = opt->value;
+       state->whitespace_option = arg;
+       parse_whitespace_option(state, arg);
        return 0;
 }
 
 static int option_parse_directory(const struct option *opt,
                                  const char *arg, int unset)
 {
-       strbuf_reset(&root);
-       strbuf_addstr(&root, arg);
-       strbuf_complete(&root, '/');
+       struct apply_state *state = opt->value;
+       strbuf_reset(&state->root);
+       strbuf_addstr(&state->root, arg);
+       strbuf_complete(&state->root, '/');
        return 0;
 }
 
-int cmd_apply(int argc, const char **argv, const char *prefix_)
+static void init_apply_state(struct apply_state *state,
+                            const char *prefix,
+                            struct lock_file *lock_file)
+{
+       memset(state, 0, sizeof(*state));
+       state->prefix = prefix;
+       state->prefix_length = state->prefix ? strlen(state->prefix) : 0;
+       state->lock_file = lock_file;
+       state->newfd = -1;
+       state->apply = 1;
+       state->line_termination = '\n';
+       state->p_value = 1;
+       state->p_context = UINT_MAX;
+       state->squelch_whitespace_errors = 5;
+       state->ws_error_action = warn_on_ws_error;
+       state->ws_ignore_action = ignore_ws_none;
+       state->linenr = 1;
+       string_list_init(&state->fn_table, 0);
+       string_list_init(&state->limit_by_name, 0);
+       string_list_init(&state->symlink_changes, 0);
+       strbuf_init(&state->root, 0);
+
+       git_apply_config();
+       if (apply_default_whitespace)
+               parse_whitespace_option(state, apply_default_whitespace);
+       if (apply_default_ignorewhitespace)
+               parse_ignorewhitespace_option(state, apply_default_ignorewhitespace);
+}
+
+static void clear_apply_state(struct apply_state *state)
+{
+       string_list_clear(&state->limit_by_name, 0);
+       string_list_clear(&state->symlink_changes, 0);
+       strbuf_release(&state->root);
+
+       /* &state->fn_table is cleared at the end of apply_patch() */
+}
+
+static void check_apply_state(struct apply_state *state, int force_apply)
+{
+       int is_not_gitdir = !startup_info->have_repository;
+
+       if (state->apply_with_reject && state->threeway)
+               die("--reject and --3way cannot be used together.");
+       if (state->cached && state->threeway)
+               die("--cached and --3way cannot be used together.");
+       if (state->threeway) {
+               if (is_not_gitdir)
+                       die(_("--3way outside a repository"));
+               state->check_index = 1;
+       }
+       if (state->apply_with_reject)
+               state->apply = state->apply_verbosely = 1;
+       if (!force_apply && (state->diffstat || state->numstat || state->summary || state->check || state->fake_ancestor))
+               state->apply = 0;
+       if (state->check_index && is_not_gitdir)
+               die(_("--index outside a repository"));
+       if (state->cached) {
+               if (is_not_gitdir)
+                       die(_("--cached outside a repository"));
+               state->check_index = 1;
+       }
+       if (state->check_index)
+               state->unsafe_paths = 0;
+       if (!state->lock_file)
+               die("BUG: state->lock_file should not be NULL");
+}
+
+static int apply_all_patches(struct apply_state *state,
+                            int argc,
+                            const char **argv,
+                            int options)
 {
        int i;
        int errs = 0;
-       int is_not_gitdir = !startup_info->have_repository;
-       int force_apply = 0;
+       int read_stdin = 1;
+
+       for (i = 0; i < argc; i++) {
+               const char *arg = argv[i];
+               int fd;
+
+               if (!strcmp(arg, "-")) {
+                       errs |= apply_patch(state, 0, "<stdin>", options);
+                       read_stdin = 0;
+                       continue;
+               } else if (0 < state->prefix_length)
+                       arg = prefix_filename(state->prefix,
+                                             state->prefix_length,
+                                             arg);
+
+               fd = open(arg, O_RDONLY);
+               if (fd < 0)
+                       die_errno(_("can't open patch '%s'"), arg);
+               read_stdin = 0;
+               set_default_whitespace_mode(state);
+               errs |= apply_patch(state, fd, arg, options);
+               close(fd);
+       }
+       set_default_whitespace_mode(state);
+       if (read_stdin)
+               errs |= apply_patch(state, 0, "<stdin>", options);
+
+       if (state->whitespace_error) {
+               if (state->squelch_whitespace_errors &&
+                   state->squelch_whitespace_errors < state->whitespace_error) {
+                       int squelched =
+                               state->whitespace_error - state->squelch_whitespace_errors;
+                       warning(Q_("squelched %d whitespace error",
+                                  "squelched %d whitespace errors",
+                                  squelched),
+                               squelched);
+               }
+               if (state->ws_error_action == die_on_ws_error)
+                       die(Q_("%d line adds whitespace errors.",
+                              "%d lines add whitespace errors.",
+                              state->whitespace_error),
+                           state->whitespace_error);
+               if (state->applied_after_fixing_ws && state->apply)
+                       warning("%d line%s applied after"
+                               " fixing whitespace errors.",
+                               state->applied_after_fixing_ws,
+                               state->applied_after_fixing_ws == 1 ? "" : "s");
+               else if (state->whitespace_error)
+                       warning(Q_("%d line adds whitespace errors.",
+                                  "%d lines add whitespace errors.",
+                                  state->whitespace_error),
+                               state->whitespace_error);
+       }
+
+       if (state->update_index) {
+               if (write_locked_index(&the_index, state->lock_file, COMMIT_LOCK))
+                       die(_("Unable to write new index file"));
+               state->newfd = -1;
+       }
+
+       return !!errs;
+}
 
-       const char *whitespace_option = NULL;
+int cmd_apply(int argc, const char **argv, const char *prefix)
+{
+       int force_apply = 0;
+       int options = 0;
+       int ret;
+       struct apply_state state;
 
        struct option builtin_apply_options[] = {
-               { OPTION_CALLBACK, 0, "exclude", NULL, N_("path"),
+               { OPTION_CALLBACK, 0, "exclude", &state, N_("path"),
                        N_("don't apply changes matching the given path"),
                        0, option_parse_exclude },
-               { OPTION_CALLBACK, 0, "include", NULL, N_("path"),
+               { OPTION_CALLBACK, 0, "include", &state, N_("path"),
                        N_("apply changes matching the given path"),
                        0, option_parse_include },
-               { OPTION_CALLBACK, 'p', NULL, NULL, N_("num"),
+               { OPTION_CALLBACK, 'p', NULL, &state, N_("num"),
                        N_("remove <num> leading slashes from traditional diff paths"),
                        0, option_parse_p },
-               OPT_BOOL(0, "no-add", &no_add,
+               OPT_BOOL(0, "no-add", &state.no_add,
                        N_("ignore additions made by the patch")),
-               OPT_BOOL(0, "stat", &diffstat,
+               OPT_BOOL(0, "stat", &state.diffstat,
                        N_("instead of applying the patch, output diffstat for the input")),
                OPT_NOOP_NOARG(0, "allow-binary-replacement"),
                OPT_NOOP_NOARG(0, "binary"),
-               OPT_BOOL(0, "numstat", &numstat,
+               OPT_BOOL(0, "numstat", &state.numstat,
                        N_("show number of added and deleted lines in decimal notation")),
-               OPT_BOOL(0, "summary", &summary,
+               OPT_BOOL(0, "summary", &state.summary,
                        N_("instead of applying the patch, output a summary for the input")),
-               OPT_BOOL(0, "check", &check,
+               OPT_BOOL(0, "check", &state.check,
                        N_("instead of applying the patch, see if the patch is applicable")),
-               OPT_BOOL(0, "index", &check_index,
+               OPT_BOOL(0, "index", &state.check_index,
                        N_("make sure the patch is applicable to the current index")),
-               OPT_BOOL(0, "cached", &cached,
+               OPT_BOOL(0, "cached", &state.cached,
                        N_("apply a patch without touching the working tree")),
-               OPT_BOOL(0, "unsafe-paths", &unsafe_paths,
+               OPT_BOOL(0, "unsafe-paths", &state.unsafe_paths,
                        N_("accept a patch that touches outside the working area")),
                OPT_BOOL(0, "apply", &force_apply,
                        N_("also apply the patch (use with --stat/--summary/--check)")),
-               OPT_BOOL('3', "3way", &threeway,
+               OPT_BOOL('3', "3way", &state.threeway,
                         N_( "attempt three-way merge if a patch does not apply")),
-               OPT_FILENAME(0, "build-fake-ancestor", &fake_ancestor,
+               OPT_FILENAME(0, "build-fake-ancestor", &state.fake_ancestor,
                        N_("build a temporary index based on embedded index information")),
                /* Think twice before adding "--nul" synonym to this */
-               OPT_SET_INT('z', NULL, &line_termination,
+               OPT_SET_INT('z', NULL, &state.line_termination,
                        N_("paths are separated with NUL character"), '\0'),
-               OPT_INTEGER('C', NULL, &p_context,
+               OPT_INTEGER('C', NULL, &state.p_context,
                                N_("ensure at least <n> lines of context match")),
-               { OPTION_CALLBACK, 0, "whitespace", &whitespace_option, N_("action"),
+               { OPTION_CALLBACK, 0, "whitespace", &state, N_("action"),
                        N_("detect new or modified lines that have whitespace errors"),
                        0, option_parse_whitespace },
-               { OPTION_CALLBACK, 0, "ignore-space-change", NULL, NULL,
+               { OPTION_CALLBACK, 0, "ignore-space-change", &state, NULL,
                        N_("ignore changes in whitespace when finding context"),
                        PARSE_OPT_NOARG, option_parse_space_change },
-               { OPTION_CALLBACK, 0, "ignore-whitespace", NULL, NULL,
+               { OPTION_CALLBACK, 0, "ignore-whitespace", &state, NULL,
                        N_("ignore changes in whitespace when finding context"),
                        PARSE_OPT_NOARG, option_parse_space_change },
-               OPT_BOOL('R', "reverse", &apply_in_reverse,
+               OPT_BOOL('R', "reverse", &state.apply_in_reverse,
                        N_("apply the patch in reverse")),
-               OPT_BOOL(0, "unidiff-zero", &unidiff_zero,
+               OPT_BOOL(0, "unidiff-zero", &state.unidiff_zero,
                        N_("don't expect at least one line of context")),
-               OPT_BOOL(0, "reject", &apply_with_reject,
+               OPT_BOOL(0, "reject", &state.apply_with_reject,
                        N_("leave the rejected hunks in corresponding *.rej files")),
-               OPT_BOOL(0, "allow-overlap", &allow_overlap,
+               OPT_BOOL(0, "allow-overlap", &state.allow_overlap,
                        N_("allow overlapping hunks")),
-               OPT__VERBOSE(&apply_verbosely, N_("be verbose")),
+               OPT__VERBOSE(&state.apply_verbosely, N_("be verbose")),
                OPT_BIT(0, "inaccurate-eof", &options,
                        N_("tolerate incorrectly detected missing new-line at the end of file"),
                        INACCURATE_EOF),
                OPT_BIT(0, "recount", &options,
                        N_("do not trust the line counts in the hunk headers"),
                        RECOUNT),
-               { OPTION_CALLBACK, 0, "directory", NULL, N_("root"),
+               { OPTION_CALLBACK, 0, "directory", &state, N_("root"),
                        N_("prepend <root> to all filenames"),
                        0, option_parse_directory },
                OPT_END()
        };
 
-       prefix = prefix_;
-       prefix_length = prefix ? strlen(prefix) : 0;
-       git_apply_config();
-       if (apply_default_whitespace)
-               parse_whitespace_option(apply_default_whitespace);
-       if (apply_default_ignorewhitespace)
-               parse_ignorewhitespace_option(apply_default_ignorewhitespace);
+       init_apply_state(&state, prefix, &lock_file);
 
-       argc = parse_options(argc, argv, prefix, builtin_apply_options,
+       argc = parse_options(argc, argv, state.prefix, builtin_apply_options,
                        apply_usage, 0);
 
-       if (apply_with_reject && threeway)
-               die("--reject and --3way cannot be used together.");
-       if (cached && threeway)
-               die("--cached and --3way cannot be used together.");
-       if (threeway) {
-               if (is_not_gitdir)
-                       die(_("--3way outside a repository"));
-               check_index = 1;
-       }
-       if (apply_with_reject)
-               apply = apply_verbosely = 1;
-       if (!force_apply && (diffstat || numstat || summary || check || fake_ancestor))
-               apply = 0;
-       if (check_index && is_not_gitdir)
-               die(_("--index outside a repository"));
-       if (cached) {
-               if (is_not_gitdir)
-                       die(_("--cached outside a repository"));
-               check_index = 1;
-       }
-       if (check_index)
-               unsafe_paths = 0;
+       check_apply_state(&state, force_apply);
 
-       for (i = 0; i < argc; i++) {
-               const char *arg = argv[i];
-               int fd;
+       ret = apply_all_patches(&state, argc, argv, options);
 
-               if (!strcmp(arg, "-")) {
-                       errs |= apply_patch(0, "<stdin>", options);
-                       read_stdin = 0;
-                       continue;
-               } else if (0 < prefix_length)
-                       arg = prefix_filename(prefix, prefix_length, arg);
+       clear_apply_state(&state);
 
-               fd = open(arg, O_RDONLY);
-               if (fd < 0)
-                       die_errno(_("can't open patch '%s'"), arg);
-               read_stdin = 0;
-               set_default_whitespace_mode(whitespace_option);
-               errs |= apply_patch(fd, arg, options);
-               close(fd);
-       }
-       set_default_whitespace_mode(whitespace_option);
-       if (read_stdin)
-               errs |= apply_patch(0, "<stdin>", options);
-       if (whitespace_error) {
-               if (squelch_whitespace_errors &&
-                   squelch_whitespace_errors < whitespace_error) {
-                       int squelched =
-                               whitespace_error - squelch_whitespace_errors;
-                       warning(Q_("squelched %d whitespace error",
-                                  "squelched %d whitespace errors",
-                                  squelched),
-                               squelched);
-               }
-               if (ws_error_action == die_on_ws_error)
-                       die(Q_("%d line adds whitespace errors.",
-                              "%d lines add whitespace errors.",
-                              whitespace_error),
-                           whitespace_error);
-               if (applied_after_fixing_ws && apply)
-                       warning("%d line%s applied after"
-                               " fixing whitespace errors.",
-                               applied_after_fixing_ws,
-                               applied_after_fixing_ws == 1 ? "" : "s");
-               else if (whitespace_error)
-                       warning(Q_("%d line adds whitespace errors.",
-                                  "%d lines add whitespace errors.",
-                                  whitespace_error),
-                               whitespace_error);
-       }
-
-       if (update_index) {
-               if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
-                       die(_("Unable to write new index file"));
-       }
-
-       return !!errs;
+       return ret;
 }