Merge branch 'ah/doc-pretty-format-fix' into maint
[gitweb.git] / diff.c
diff --git a/diff.c b/diff.c
index 71f0274ce0df2e6af8cd144c78c64dbb694c1ab7..74283d9001fbc48d11ba5c449ea7c16692791c88 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -2,6 +2,7 @@
  * Copyright (C) 2005 Junio C Hamano
  */
 #include "cache.h"
+#include "tempfile.h"
 #include "quote.h"
 #include "diff.h"
 #include "diffcore.h"
 #include "run-command.h"
 #include "utf8.h"
 #include "userdiff.h"
-#include "sigchain.h"
+#include "submodule-config.h"
 #include "submodule.h"
 #include "ll-merge.h"
 #include "string-list.h"
 #include "argv-array.h"
+#include "graph.h"
 
 #ifdef NO_FAST_WORKING_DIRECTORY
 #define FAST_WORKING_DIRECTORY 0
 #endif
 
 static int diff_detect_rename_default;
+static int diff_indent_heuristic; /* experimental */
 static int diff_rename_limit_default = 400;
 static int diff_suppress_blank_empty;
 static int diff_use_color_default = -1;
 static int diff_context_default = 3;
+static int diff_interhunk_context_default;
 static const char *diff_word_regex_cfg;
 static const char *external_diff_cmd_cfg;
 static const char *diff_order_file_cfg;
@@ -39,6 +43,7 @@ static int diff_stat_graph_width;
 static int diff_dirstat_permille_default = 30;
 static struct diff_options default_diff_options;
 static long diff_algorithm;
+static unsigned ws_error_highlight_default = WSEH_NEW;
 
 static char diff_colors[][COLOR_MAXLEN] = {
        GIT_COLOR_RESET,
@@ -52,6 +57,11 @@ static char diff_colors[][COLOR_MAXLEN] = {
        GIT_COLOR_NORMAL,       /* FUNCINFO */
 };
 
+static NORETURN void die_want_option(const char *option_name)
+{
+       die(_("option '%s' requires a value"), option_name);
+}
+
 static int parse_diff_color_slot(const char *var)
 {
        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
@@ -129,9 +139,11 @@ static int parse_dirstat_params(struct diff_options *options, const char *params
 static int parse_submodule_params(struct diff_options *options, const char *value)
 {
        if (!strcmp(value, "log"))
-               DIFF_OPT_SET(options, SUBMODULE_LOG);
+               options->submodule_format = DIFF_SUBMODULE_LOG;
        else if (!strcmp(value, "short"))
-               DIFF_OPT_CLR(options, SUBMODULE_LOG);
+               options->submodule_format = DIFF_SUBMODULE_SHORT;
+       else if (!strcmp(value, "diff"))
+               options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
        else
                return -1;
        return 0;
@@ -161,12 +173,61 @@ long parse_algorithm_value(const char *value)
        return -1;
 }
 
+static int parse_one_token(const char **arg, const char *token)
+{
+       const char *rest;
+       if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
+               *arg = rest;
+               return 1;
+       }
+       return 0;
+}
+
+static int parse_ws_error_highlight(const char *arg)
+{
+       const char *orig_arg = arg;
+       unsigned val = 0;
+
+       while (*arg) {
+               if (parse_one_token(&arg, "none"))
+                       val = 0;
+               else if (parse_one_token(&arg, "default"))
+                       val = WSEH_NEW;
+               else if (parse_one_token(&arg, "all"))
+                       val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
+               else if (parse_one_token(&arg, "new"))
+                       val |= WSEH_NEW;
+               else if (parse_one_token(&arg, "old"))
+                       val |= WSEH_OLD;
+               else if (parse_one_token(&arg, "context"))
+                       val |= WSEH_CONTEXT;
+               else {
+                       return -1 - (int)(arg - orig_arg);
+               }
+               if (*arg)
+                       arg++;
+       }
+       return val;
+}
+
 /*
  * These are to give UI layer defaults.
  * The core-level commands such as git-diff-files should
  * never be affected by the setting of diff.renames
  * the user happens to have in the configuration file.
  */
+void init_diff_ui_defaults(void)
+{
+       diff_detect_rename_default = 1;
+}
+
+int git_diff_heuristic_config(const char *var, const char *value, void *cb)
+{
+       if (!strcmp(var, "diff.indentheuristic"))
+               diff_indent_heuristic = git_config_bool(var, value);
+       return 0;
+}
+
 int git_diff_ui_config(const char *var, const char *value, void *cb)
 {
        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
@@ -179,6 +240,12 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
                        return -1;
                return 0;
        }
+       if (!strcmp(var, "diff.interhunkcontext")) {
+               diff_interhunk_context_default = git_config_int(var, value);
+               if (diff_interhunk_context_default < 0)
+                       return -1;
+               return 0;
+       }
        if (!strcmp(var, "diff.renames")) {
                diff_detect_rename_default = git_config_rename(var, value);
                return 0;
@@ -223,6 +290,17 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
                return 0;
        }
 
+       if (git_diff_heuristic_config(var, value, cb) < 0)
+               return -1;
+
+       if (!strcmp(var, "diff.wserrorhighlight")) {
+               int val = parse_ws_error_highlight(value);
+               if (val < 0)
+                       return -1;
+               ws_error_highlight_default = val;
+               return 0;
+       }
+
        if (git_color_config(var, value, cb) < 0)
                return -1;
 
@@ -308,11 +386,26 @@ static const char *external_diff(void)
        return external_diff_cmd;
 }
 
+/*
+ * Keep track of files used for diffing. Sometimes such an entry
+ * refers to a temporary file, sometimes to an existing file, and
+ * sometimes to "/dev/null".
+ */
 static struct diff_tempfile {
-       const char *name; /* filename external diff should read from */
-       char hex[41];
+       /*
+        * filename external diff should read from, or NULL if this
+        * entry is currently not in use:
+        */
+       const char *name;
+
+       char hex[GIT_MAX_HEXSZ + 1];
        char mode[10];
-       char tmp_path[PATH_MAX];
+
+       /*
+        * If this diff_tempfile instance refers to a temporary file,
+        * this tempfile object is used to manage its lifetime.
+        */
+       struct tempfile tempfile;
 } diff_temp[2];
 
 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
@@ -328,7 +421,6 @@ struct emit_callback {
        const char **label_path;
        struct diff_words_data *diff_words;
        struct diff_options *opt;
-       int *found_changesp;
        struct strbuf *header;
 };
 
@@ -597,25 +689,16 @@ static struct diff_tempfile *claim_diff_tempfile(void) {
        die("BUG: diff is failing to clean up its tempfiles");
 }
 
-static int remove_tempfile_installed;
-
 static void remove_tempfile(void)
 {
        int i;
        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
-               if (diff_temp[i].name == diff_temp[i].tmp_path)
-                       unlink_or_warn(diff_temp[i].name);
+               if (is_tempfile_active(&diff_temp[i].tempfile))
+                       delete_tempfile(&diff_temp[i].tempfile);
                diff_temp[i].name = NULL;
        }
 }
 
-static void remove_tempfile_on_signal(int signo)
-{
-       remove_tempfile();
-       sigchain_pop(signo);
-       raise(signo);
-}
-
 static void print_line_count(FILE *file, int count)
 {
        switch (count) {
@@ -705,7 +788,6 @@ static void emit_rewrite_diff(const char *name_a,
 
        memset(&ecbdata, 0, sizeof(ecbdata));
        ecbdata.color_diff = want_color(o->use_color);
-       ecbdata.found_changesp = &o->found_changes;
        ecbdata.ws_rule = whitespace_rule(name_b);
        ecbdata.opt = o;
        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
@@ -829,7 +911,7 @@ static int fn_out_diff_words_write_helper(FILE *fp,
 /*
  * '--color-words' algorithm can be described as:
  *
- *   1. collect the minus/plus lines of a diff hunk, divided into
+ *   1. collect the minus/plus lines of a diff hunk, divided into
  *      minus-lines and plus-lines;
  *
  *   2. break both minus-lines and plus-lines into words and
@@ -934,7 +1016,8 @@ static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 {
        if (word_regex && *begin < buffer->size) {
                regmatch_t match[1];
-               if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
+               if (!regexec_buf(word_regex, buffer->ptr + *begin,
+                                buffer->size - *begin, 1, match, 0)) {
                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
                                        '\n', match[0].rm_eo - match[0].rm_so);
                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
@@ -1199,12 +1282,13 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
        struct diff_options *o = ecbdata->opt;
        const char *line_prefix = diff_line_prefix(o);
 
+       o->found_changes = 1;
+
        if (ecbdata->header) {
-               fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
+               fprintf(o->file, "%s", ecbdata->header->buf);
                strbuf_reset(ecbdata->header);
                ecbdata->header = NULL;
        }
-       *(ecbdata->found_changesp) = 1;
 
        if (ecbdata->label_path[0]) {
                const char *name_a_tab, *name_b_tab;
@@ -1212,9 +1296,9 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 
-               fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
+               fprintf(o->file, "%s%s--- %s%s%s\n",
                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
-               fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
+               fprintf(o->file, "%s%s+++ %s%s%s\n",
                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
        }
@@ -1232,15 +1316,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                find_lno(line, ecbdata);
                emit_hunk_header(ecbdata, line, len);
                if (line[len-1] != '\n')
-                       putc('\n', ecbdata->opt->file);
-               return;
-       }
-
-       if (len < 1) {
-               emit_line(ecbdata->opt, reset, reset, line, len);
-               if (ecbdata->diff_words
-                   && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
-                       fputs("~\n", ecbdata->opt->file);
+                       putc('\n', o->file);
                return;
        }
 
@@ -1265,8 +1341,8 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                }
                diff_words_flush(ecbdata);
                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
-                       emit_line(ecbdata->opt, context, reset, line, len);
-                       fputs("~\n", ecbdata->opt->file);
+                       emit_line(o, context, reset, line, len);
+                       fputs("~\n", o->file);
                } else {
                        /*
                         * Skip the prefix character, if any.  With
@@ -1277,7 +1353,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                              line++;
                              len--;
                        }
-                       emit_line(ecbdata->opt, context, reset, line, len);
+                       emit_line(o, context, reset, line, len);
                }
                return;
        }
@@ -1299,8 +1375,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
        default:
                /* incomplete line at the end */
                ecbdata->lno_in_preimage++;
-               emit_line(ecbdata->opt,
-                         diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
+               emit_line(o, diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
                          reset, line, len);
                break;
        }
@@ -1608,7 +1683,7 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
         */
 
        if (options->stat_width == -1)
-               width = term_columns() - options->output_prefix_length;
+               width = term_columns() - strlen(line_prefix);
        else
                width = options->stat_width ? options->stat_width : 80;
        number_width = decimal_width(max_change) > number_width ?
@@ -1916,8 +1991,8 @@ static void show_dirstat(struct diff_options *options)
 
                name = p->two->path ? p->two->path : p->one->path;
 
-               if (p->one->sha1_valid && p->two->sha1_valid)
-                       content_changed = hashcmp(p->one->sha1, p->two->sha1);
+               if (p->one->oid_valid && p->two->oid_valid)
+                       content_changed = oidcmp(&p->one->oid, &p->two->oid);
                else
                        content_changed = 1;
 
@@ -1946,7 +2021,7 @@ static void show_dirstat(struct diff_options *options)
                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
                        diff_populate_filespec(p->one, 0);
                        diff_populate_filespec(p->two, 0);
-                       diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
+                       diffcore_count_changes(p->one, p->two, NULL, NULL,
                                               &copied, &added);
                        diff_free_filespec_data(p->one);
                        diff_free_filespec_data(p->two);
@@ -1989,7 +2064,7 @@ static void show_dirstat(struct diff_options *options)
                return;
 
        /* Show all directories with more than x% of the changes */
-       qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
+       QSORT(dir.files, dir.nr, dirstat_compare);
        gather_dirstat(options, &dir, changed, "", 0);
 }
 
@@ -2033,7 +2108,7 @@ static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *o
                return;
 
        /* Show all directories with more than x% of the changes */
-       qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
+       QSORT(dir.files, dir.nr, dirstat_compare);
        gather_dirstat(options, &dir, changed, "", 0);
 }
 
@@ -2282,16 +2357,37 @@ static void builtin_diff(const char *name_a,
        struct strbuf header = STRBUF_INIT;
        const char *line_prefix = diff_line_prefix(o);
 
-       if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
-                       (!one->mode || S_ISGITLINK(one->mode)) &&
-                       (!two->mode || S_ISGITLINK(two->mode))) {
+       diff_set_mnemonic_prefix(o, "a/", "b/");
+       if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
+               a_prefix = o->b_prefix;
+               b_prefix = o->a_prefix;
+       } else {
+               a_prefix = o->a_prefix;
+               b_prefix = o->b_prefix;
+       }
+
+       if (o->submodule_format == DIFF_SUBMODULE_LOG &&
+           (!one->mode || S_ISGITLINK(one->mode)) &&
+           (!two->mode || S_ISGITLINK(two->mode))) {
                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
                show_submodule_summary(o->file, one->path ? one->path : two->path,
                                line_prefix,
-                               one->sha1, two->sha1, two->dirty_submodule,
+                               &one->oid, &two->oid,
+                               two->dirty_submodule,
                                meta, del, add, reset);
                return;
+       } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
+                  (!one->mode || S_ISGITLINK(one->mode)) &&
+                  (!two->mode || S_ISGITLINK(two->mode))) {
+               const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
+               const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
+               show_submodule_inline_diff(o->file, one->path ? one->path : two->path,
+                               line_prefix,
+                               &one->oid, &two->oid,
+                               two->dirty_submodule,
+                               meta, del, add, reset, o);
+               return;
        }
 
        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
@@ -2299,15 +2395,6 @@ static void builtin_diff(const char *name_a,
                textconv_two = get_textconv(two);
        }
 
-       diff_set_mnemonic_prefix(o, "a/", "b/");
-       if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
-               a_prefix = o->b_prefix;
-               b_prefix = o->a_prefix;
-       } else {
-               a_prefix = o->a_prefix;
-               b_prefix = o->b_prefix;
-       }
-
        /* Never use a non-valid filename anywhere if at all possible */
        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
@@ -2367,7 +2454,7 @@ static void builtin_diff(const char *name_a,
                if (!one->data && !two->data &&
                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
                    !DIFF_OPT_TST(o, BINARY)) {
-                       if (!hashcmp(one->sha1, two->sha1)) {
+                       if (!oidcmp(&one->oid, &two->oid)) {
                                if (must_show_header)
                                        fprintf(o->file, "%s", header.buf);
                                goto free_ab_and_return;
@@ -2420,7 +2507,6 @@ static void builtin_diff(const char *name_a,
                memset(&ecbdata, 0, sizeof(ecbdata));
                ecbdata.label_path = lbl;
                ecbdata.color_diff = want_color(o->use_color);
-               ecbdata.found_changesp = &o->found_changes;
                ecbdata.ws_rule = whitespace_rule(name_b);
                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
@@ -2488,7 +2574,7 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
                return;
        }
 
-       same_contents = !hashcmp(one->sha1, two->sha1);
+       same_contents = !oidcmp(&one->oid, &two->oid);
 
        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
                data->is_binary = 1;
@@ -2600,12 +2686,9 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
 
 struct diff_filespec *alloc_filespec(const char *path)
 {
-       int namelen = strlen(path);
-       struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
+       struct diff_filespec *spec;
 
-       memset(spec, 0, sizeof(*spec));
-       spec->path = (char *)(spec + 1);
-       memcpy(spec->path, path, namelen+1);
+       FLEXPTR_ALLOC_STR(spec, path, path);
        spec->count = 1;
        spec->is_binary = -1;
        return spec;
@@ -2624,8 +2707,8 @@ void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 {
        if (mode) {
                spec->mode = canon_mode(mode);
-               hashcpy(spec->sha1, sha1);
-               spec->sha1_valid = sha1_valid;
+               hashcpy(spec->oid.hash, sha1);
+               spec->oid_valid = sha1_valid;
        }
 }
 
@@ -2668,6 +2751,13 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
                return 0;
 
+       /*
+        * Similarly, if we'd have to convert the file contents anyway, that
+        * makes the optimization not worthwhile.
+        */
+       if (!want_file && would_convert_to_git(name))
+               return 0;
+
        len = strlen(name);
        pos = cache_name_pos(name, len);
        if (pos < 0)
@@ -2678,7 +2768,7 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
         * This is not the sha1 we are looking for, or
         * unreusable because it is not a regular file.
         */
-       if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
+       if (hashcmp(sha1, ce->oid.hash) || !S_ISREG(ce->ce_mode))
                return 0;
 
        /*
@@ -2700,21 +2790,22 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
 
 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
 {
-       int len;
-       char *data = xmalloc(100), *dirty = "";
+       struct strbuf buf = STRBUF_INIT;
+       char *dirty = "";
 
        /* Are we looking at the work tree? */
        if (s->dirty_submodule)
                dirty = "-dirty";
 
-       len = snprintf(data, 100,
-                      "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
-       s->data = data;
-       s->size = len;
-       s->should_free = 1;
+       strbuf_addf(&buf, "Subproject commit %s%s\n",
+                   oid_to_hex(&s->oid), dirty);
+       s->size = buf.len;
        if (size_only) {
                s->data = NULL;
-               free(data);
+               strbuf_release(&buf);
+       } else {
+               s->data = strbuf_detach(&buf, NULL);
+               s->should_free = 1;
        }
        return 0;
 }
@@ -2750,8 +2841,8 @@ int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
        if (S_ISGITLINK(s->mode))
                return diff_populate_gitlink(s, size_only);
 
-       if (!s->sha1_valid ||
-           reuse_worktree_file(s->path, s->sha1, 0)) {
+       if (!s->oid_valid ||
+           reuse_worktree_file(s->path, s->oid.hash, 0)) {
                struct strbuf buf = STRBUF_INIT;
                struct stat st;
                int fd;
@@ -2779,8 +2870,25 @@ int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
                        s->should_free = 1;
                        return 0;
                }
-               if (size_only)
+
+               /*
+                * Even if the caller would be happy with getting
+                * only the size, we cannot return early at this
+                * point if the path requires us to run the content
+                * conversion.
+                */
+               if (size_only && !would_convert_to_git(s->path))
                        return 0;
+
+               /*
+                * Note: this check uses xsize_t(st.st_size) that may
+                * not be the true size of the blob after it goes
+                * through convert_to_git().  This may not strictly be
+                * correct, but the whole point of big_file_threshold
+                * and is_binary check being that we want to avoid
+                * opening the file and inspecting the contents, this
+                * is probably fine.
+                */
                if ((flags & CHECK_BINARY) &&
                    s->size > big_file_threshold && s->is_binary == -1) {
                        s->is_binary = 1;
@@ -2808,9 +2916,10 @@ int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
        else {
                enum object_type type;
                if (size_only || (flags & CHECK_BINARY)) {
-                       type = sha1_object_info(s->sha1, &s->size);
+                       type = sha1_object_info(s->oid.hash, &s->size);
                        if (type < 0)
-                               die("unable to read %s", sha1_to_hex(s->sha1));
+                               die("unable to read %s",
+                                   oid_to_hex(&s->oid));
                        if (size_only)
                                return 0;
                        if (s->size > big_file_threshold && s->is_binary == -1) {
@@ -2818,9 +2927,9 @@ int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
                                return 0;
                        }
                }
-               s->data = read_sha1_file(s->sha1, &type, &s->size);
+               s->data = read_sha1_file(s->oid.hash, &type, &s->size);
                if (!s->data)
-                       die("unable to read %s", sha1_to_hex(s->sha1));
+                       die("unable to read %s", oid_to_hex(&s->oid));
                s->should_free = 1;
        }
        return 0;
@@ -2849,7 +2958,7 @@ void diff_free_filespec_data(struct diff_filespec *s)
 static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
                           void *blob,
                           unsigned long size,
-                          const unsigned char *sha1,
+                          const struct object_id *oid,
                           int mode)
 {
        int fd;
@@ -2862,8 +2971,7 @@ static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
        strbuf_addstr(&template, "XXXXXX_");
        strbuf_addstr(&template, base);
 
-       fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
-                       strlen(base) + 1);
+       fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
        if (fd < 0)
                die_errno("unable to create temp-file");
        if (convert_to_working_tree(path,
@@ -2873,11 +2981,10 @@ static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
        }
        if (write_in_full(fd, blob, size) != size)
                die_errno("unable to write temp-file");
-       close(fd);
-       temp->name = temp->tmp_path;
-       strcpy(temp->hex, sha1_to_hex(sha1));
-       temp->hex[40] = 0;
-       sprintf(temp->mode, "%06o", mode);
+       close_tempfile(&temp->tempfile);
+       temp->name = get_tempfile_path(&temp->tempfile);
+       oid_to_hex_r(temp->hex, oid);
+       xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
        strbuf_release(&buf);
        strbuf_release(&template);
        free(path_dup);
@@ -2894,20 +3001,14 @@ static struct diff_tempfile *prepare_temp_file(const char *name,
                 * a '+' entry produces this for file-1.
                 */
                temp->name = "/dev/null";
-               strcpy(temp->hex, ".");
-               strcpy(temp->mode, ".");
+               xsnprintf(temp->hex, sizeof(temp->hex), ".");
+               xsnprintf(temp->mode, sizeof(temp->mode), ".");
                return temp;
        }
 
-       if (!remove_tempfile_installed) {
-               atexit(remove_tempfile);
-               sigchain_push_common(remove_tempfile_on_signal);
-               remove_tempfile_installed = 1;
-       }
-
        if (!S_ISGITLINK(one->mode) &&
-           (!one->sha1_valid ||
-            reuse_worktree_file(name, one->sha1, 1))) {
+           (!one->oid_valid ||
+            reuse_worktree_file(name, one->oid.hash, 1))) {
                struct stat st;
                if (lstat(name, &st) < 0) {
                        if (errno == ENOENT)
@@ -2919,26 +3020,26 @@ static struct diff_tempfile *prepare_temp_file(const char *name,
                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
                                die_errno("readlink(%s)", name);
                        prep_temp_blob(name, temp, sb.buf, sb.len,
-                                      (one->sha1_valid ?
-                                       one->sha1 : null_sha1),
-                                      (one->sha1_valid ?
+                                      (one->oid_valid ?
+                                       &one->oid : &null_oid),
+                                      (one->oid_valid ?
                                        one->mode : S_IFLNK));
                        strbuf_release(&sb);
                }
                else {
                        /* we can borrow from the file in the work tree */
                        temp->name = name;
-                       if (!one->sha1_valid)
-                               strcpy(temp->hex, sha1_to_hex(null_sha1));
+                       if (!one->oid_valid)
+                               sha1_to_hex_r(temp->hex, null_sha1);
                        else
-                               strcpy(temp->hex, sha1_to_hex(one->sha1));
+                               oid_to_hex_r(temp->hex, &one->oid);
                        /* Even though we may sometimes borrow the
                         * contents from the work tree, we always want
                         * one->mode.  mode is trustworthy even when
                         * !(one->sha1_valid), as long as
                         * DIFF_FILE_VALID(one).
                         */
-                       sprintf(temp->mode, "%06o", one->mode);
+                       xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
                }
                return temp;
        }
@@ -2946,7 +3047,7 @@ static struct diff_tempfile *prepare_temp_file(const char *name,
                if (diff_populate_filespec(one, 0))
                        die("cannot read data blob for %s", one->path);
                prep_temp_blob(name, temp, one->data, one->size,
-                              one->sha1, one->mode);
+                              &one->oid, one->mode);
        }
        return temp;
 }
@@ -3010,6 +3111,22 @@ static int similarity_index(struct diff_filepair *p)
        return p->score * 100 / MAX_SCORE;
 }
 
+static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
+{
+       if (startup_info->have_repository)
+               return find_unique_abbrev(oid->hash, abbrev);
+       else {
+               char *hex = oid_to_hex(oid);
+               if (abbrev < 0)
+                       abbrev = FALLBACK_DEFAULT_ABBREV;
+               if (abbrev > GIT_SHA1_HEXSZ)
+                       die("BUG: oid abbreviation out of range: %d", abbrev);
+               if (abbrev)
+                       hex[abbrev] = '\0';
+               return hex;
+       }
+}
+
 static void fill_metainfo(struct strbuf *msg,
                          const char *name,
                          const char *other,
@@ -3059,7 +3176,7 @@ static void fill_metainfo(struct strbuf *msg,
        default:
                *must_show_header = 0;
        }
-       if (one && two && hashcmp(one->sha1, two->sha1)) {
+       if (one && two && oidcmp(&one->oid, &two->oid)) {
                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
 
                if (DIFF_OPT_TST(o, BINARY)) {
@@ -3068,9 +3185,9 @@ static void fill_metainfo(struct strbuf *msg,
                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
                                abbrev = 40;
                }
-               strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
-                           find_unique_abbrev(one->sha1, abbrev));
-               strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
+               strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
+                           diff_abbrev_oid(&one->oid, abbrev),
+                           diff_abbrev_oid(&two->oid, abbrev));
                if (one->mode == two->mode)
                        strbuf_addf(msg, " %06o", one->mode);
                strbuf_addf(msg, "%s\n", reset);
@@ -3125,20 +3242,20 @@ static void run_diff_cmd(const char *pgm,
 static void diff_fill_sha1_info(struct diff_filespec *one)
 {
        if (DIFF_FILE_VALID(one)) {
-               if (!one->sha1_valid) {
+               if (!one->oid_valid) {
                        struct stat st;
                        if (one->is_stdin) {
-                               hashcpy(one->sha1, null_sha1);
+                               oidclr(&one->oid);
                                return;
                        }
                        if (lstat(one->path, &st) < 0)
                                die_errno("stat '%s'", one->path);
-                       if (index_path(one->sha1, one->path, &st, 0))
+                       if (index_path(one->oid.hash, one->path, &st, 0))
                                die("cannot hash %s", one->path);
                }
        }
        else
-               hashclr(one->sha1);
+               oidclr(&one->oid);
 }
 
 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
@@ -3263,12 +3380,14 @@ void diff_setup(struct diff_options *options)
 
        options->file = stdout;
 
+       options->abbrev = DEFAULT_ABBREV;
        options->line_termination = '\n';
        options->break_opt = -1;
        options->rename_limit = -1;
        options->dirstat_permille = diff_dirstat_permille_default;
        options->context = diff_context_default;
-       options->ws_error_highlight = WSEH_NEW;
+       options->interhunkcontext = diff_interhunk_context_default;
+       options->ws_error_highlight = ws_error_highlight_default;
        DIFF_OPT_SET(options, RENAME_EMPTY);
 
        /* pathchange left =NULL by default */
@@ -3277,6 +3396,8 @@ void diff_setup(struct diff_options *options)
        options->use_color = diff_use_color_default;
        options->detect_rename = diff_detect_rename_default;
        options->xdl_opts |= diff_algorithm;
+       if (diff_indent_heuristic)
+               DIFF_XDL_SET(options, INDENT_HEURISTIC);
 
        options->orderfile = diff_order_file_cfg;
 
@@ -3304,7 +3425,7 @@ void diff_setup_done(struct diff_options *options)
        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
                count++;
        if (count > 1)
-               die("--name-only, --name-status, --check and -s are mutually exclusive");
+               die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
 
        /*
         * Most of the time we can say "there are changes"
@@ -3378,7 +3499,7 @@ void diff_setup_done(struct diff_options *options)
                         */
                        read_cache();
        }
-       if (options->abbrev <= 0 || 40 < options->abbrev)
+       if (40 < options->abbrev)
                options->abbrev = 40; /* full */
 
        /*
@@ -3500,7 +3621,7 @@ static int stat_opt(struct diff_options *options, const char **av)
                        if (*arg == '=')
                                width = strtoul(arg + 1, &end, 10);
                        else if (!*arg && !av[1])
-                               die("Option '--stat-width' requires a value");
+                               die_want_option("--stat-width");
                        else if (!*arg) {
                                width = strtoul(av[1], &end, 10);
                                argcount = 2;
@@ -3509,7 +3630,7 @@ static int stat_opt(struct diff_options *options, const char **av)
                        if (*arg == '=')
                                name_width = strtoul(arg + 1, &end, 10);
                        else if (!*arg && !av[1])
-                               die("Option '--stat-name-width' requires a value");
+                               die_want_option("--stat-name-width");
                        else if (!*arg) {
                                name_width = strtoul(av[1], &end, 10);
                                argcount = 2;
@@ -3518,7 +3639,7 @@ static int stat_opt(struct diff_options *options, const char **av)
                        if (*arg == '=')
                                graph_width = strtoul(arg + 1, &end, 10);
                        else if (!*arg && !av[1])
-                               die("Option '--stat-graph-width' requires a value");
+                               die_want_option("--stat-graph-width");
                        else if (!*arg) {
                                graph_width = strtoul(av[1], &end, 10);
                                argcount = 2;
@@ -3527,7 +3648,7 @@ static int stat_opt(struct diff_options *options, const char **av)
                        if (*arg == '=')
                                count = strtoul(arg + 1, &end, 10);
                        else if (!*arg && !av[1])
-                               die("Option '--stat-count' requires a value");
+                               die_want_option("--stat-count");
                        else if (!*arg) {
                                count = strtoul(av[1], &end, 10);
                                argcount = 2;
@@ -3655,51 +3776,29 @@ static void enable_patch_output(int *fmt) {
        *fmt |= DIFF_FORMAT_PATCH;
 }
 
-static int parse_one_token(const char **arg, const char *token)
+static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
 {
-       const char *rest;
-       if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
-               *arg = rest;
-               return 1;
-       }
-       return 0;
-}
+       int val = parse_ws_error_highlight(arg);
 
-static int parse_ws_error_highlight(struct diff_options *opt, const char *arg)
-{
-       const char *orig_arg = arg;
-       unsigned val = 0;
-       while (*arg) {
-               if (parse_one_token(&arg, "none"))
-                       val = 0;
-               else if (parse_one_token(&arg, "default"))
-                       val = WSEH_NEW;
-               else if (parse_one_token(&arg, "all"))
-                       val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
-               else if (parse_one_token(&arg, "new"))
-                       val |= WSEH_NEW;
-               else if (parse_one_token(&arg, "old"))
-                       val |= WSEH_OLD;
-               else if (parse_one_token(&arg, "context"))
-                       val |= WSEH_CONTEXT;
-               else {
-                       error("unknown value after ws-error-highlight=%.*s",
-                             (int)(arg - orig_arg), orig_arg);
-                       return 0;
-               }
-               if (*arg)
-                       arg++;
+       if (val < 0) {
+               error("unknown value after ws-error-highlight=%.*s",
+                     -1 - val, arg);
+               return 0;
        }
        opt->ws_error_highlight = val;
        return 1;
 }
 
-int diff_opt_parse(struct diff_options *options, const char **av, int ac)
+int diff_opt_parse(struct diff_options *options,
+                  const char **av, int ac, const char *prefix)
 {
        const char *arg = av[0];
        const char *optarg;
        int argcount;
 
+       if (!prefix)
+               prefix = "";
+
        /* Output format options */
        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
            || opt_arg(arg, 'U', "unified", &options->context))
@@ -3793,6 +3892,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
        else if (!strcmp(arg, "--ignore-blank-lines"))
                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
+       else if (!strcmp(arg, "--indent-heuristic"))
+               DIFF_XDL_SET(options, INDENT_HEURISTIC);
+       else if (!strcmp(arg, "--no-indent-heuristic"))
+               DIFF_XDL_CLR(options, INDENT_HEURISTIC);
        else if (!strcmp(arg, "--patience"))
                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
        else if (!strcmp(arg, "--histogram"))
@@ -3824,9 +3927,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
        else if (!strcmp(arg, "--follow"))
                DIFF_OPT_SET(options, FOLLOW_RENAMES);
-       else if (!strcmp(arg, "--no-follow"))
+       else if (!strcmp(arg, "--no-follow")) {
                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
-       else if (!strcmp(arg, "--color"))
+               DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
+       } else if (!strcmp(arg, "--color"))
                options->use_color = 1;
        else if (skip_prefix(arg, "--color=", &arg)) {
                int value = git_config_colorbool(NULL, arg);
@@ -3888,11 +3992,15 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
                handle_ignore_submodules_arg(options, arg);
        } else if (!strcmp(arg, "--submodule"))
-               DIFF_OPT_SET(options, SUBMODULE_LOG);
+               options->submodule_format = DIFF_SUBMODULE_LOG;
        else if (skip_prefix(arg, "--submodule=", &arg))
                return parse_submodule_opt(options, arg);
        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
-               return parse_ws_error_highlight(options, arg);
+               return parse_ws_error_highlight_opt(options, arg);
+       else if (!strcmp(arg, "--ita-invisible-in-index"))
+               options->ita_invisible_in_index = 1;
+       else if (!strcmp(arg, "--ita-visible-in-index"))
+               options->ita_invisible_in_index = 0;
 
        /* misc options */
        else if (!strcmp(arg, "-z"))
@@ -3915,7 +4023,7 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
        else if (!strcmp(arg, "--pickaxe-regex"))
                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
        else if ((argcount = short_opt('O', av, &optarg))) {
-               options->orderfile = optarg;
+               options->orderfile = prefix_filename(prefix, optarg);
                return argcount;
        }
        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
@@ -3925,6 +4033,8 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                            offending, optarg);
                return argcount;
        }
+       else if (!strcmp(arg, "--no-abbrev"))
+               options->abbrev = 0;
        else if (!strcmp(arg, "--abbrev"))
                options->abbrev = DEFAULT_ABBREV;
        else if (skip_prefix(arg, "--abbrev=", &arg)) {
@@ -3938,6 +4048,12 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                options->a_prefix = optarg;
                return argcount;
        }
+       else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
+               options->line_prefix = optarg;
+               options->line_prefix_length = strlen(options->line_prefix);
+               graph_setup_line_prefix(options);
+               return argcount;
+       }
        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
                options->b_prefix = optarg;
                return argcount;
@@ -3954,10 +4070,14 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
        else if (!strcmp(arg, "--no-function-context"))
                DIFF_OPT_CLR(options, FUNCCONTEXT);
        else if ((argcount = parse_long_opt("output", av, &optarg))) {
-               options->file = fopen(optarg, "w");
+               char *path = prefix_filename(prefix, optarg);
+               options->file = fopen(path, "w");
                if (!options->file)
-                       die_errno("Could not open '%s'", optarg);
+                       die_errno("Could not open '%s'", path);
                options->close_file = 1;
+               if (options->use_color != GIT_COLOR_ALWAYS)
+                       options->use_color = GIT_COLOR_NEVER;
+               free(path);
                return argcount;
        } else
                return 0;
@@ -4068,27 +4188,46 @@ void diff_free_filepair(struct diff_filepair *p)
        free(p);
 }
 
-/* This is different from find_unique_abbrev() in that
- * it stuffs the result with dots for alignment.
- */
-const char *diff_unique_abbrev(const unsigned char *sha1, int len)
+const char *diff_aligned_abbrev(const struct object_id *oid, int len)
 {
        int abblen;
        const char *abbrev;
-       if (len == 40)
-               return sha1_to_hex(sha1);
 
-       abbrev = find_unique_abbrev(sha1, len);
+       if (len == GIT_SHA1_HEXSZ)
+               return oid_to_hex(oid);
+
+       abbrev = diff_abbrev_oid(oid, len);
        abblen = strlen(abbrev);
-       if (abblen < 37) {
-               static char hex[41];
+
+       /*
+        * In well-behaved cases, where the abbbreviated result is the
+        * same as the requested length, append three dots after the
+        * abbreviation (hence the whole logic is limited to the case
+        * where abblen < 37); when the actual abbreviated result is a
+        * bit longer than the requested length, we reduce the number
+        * of dots so that they match the well-behaved ones.  However,
+        * if the actual abbreviation is longer than the requested
+        * length by more than three, we give up on aligning, and add
+        * three dots anyway, to indicate that the output is not the
+        * full object name.  Yes, this may be suboptimal, but this
+        * appears only in "diff --raw --abbrev" output and it is not
+        * worth the effort to change it now.  Note that this would
+        * likely to work fine when the automatic sizing of default
+        * abbreviation length is used--we would be fed -1 in "len" in
+        * that case, and will end up always appending three-dots, but
+        * the automatic sizing is supposed to give abblen that ensures
+        * uniqueness across all objects (statistically speaking).
+        */
+       if (abblen < GIT_SHA1_HEXSZ - 3) {
+               static char hex[GIT_MAX_HEXSZ + 1];
                if (len < abblen && abblen <= len + 2)
-                       sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
+                       xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
                else
-                       sprintf(hex, "%s...", abbrev);
+                       xsnprintf(hex, sizeof(hex), "%s...", abbrev);
                return hex;
        }
-       return sha1_to_hex(sha1);
+
+       return oid_to_hex(oid);
 }
 
 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
@@ -4099,8 +4238,9 @@ static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
        fprintf(opt->file, "%s", diff_line_prefix(opt));
        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
-                       diff_unique_abbrev(p->one->sha1, opt->abbrev));
-               fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
+                       diff_aligned_abbrev(&p->one->oid, opt->abbrev));
+               fprintf(opt->file, "%s ",
+                       diff_aligned_abbrev(&p->two->oid, opt->abbrev));
        }
        if (p->score) {
                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
@@ -4149,11 +4289,11 @@ int diff_unmodified_pair(struct diff_filepair *p)
        /* both are valid and point at the same path.  that is, we are
         * dealing with a change.
         */
-       if (one->sha1_valid && two->sha1_valid &&
-           !hashcmp(one->sha1, two->sha1) &&
+       if (one->oid_valid && two->oid_valid &&
+           !oidcmp(&one->oid, &two->oid) &&
            !one->dirty_submodule && !two->dirty_submodule)
                return 1; /* no change */
-       if (!one->sha1_valid && !two->sha1_valid)
+       if (!one->oid_valid && !two->oid_valid)
                return 1; /* both look at the same file on the filesystem. */
        return 0;
 }
@@ -4214,7 +4354,7 @@ void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
                s->path,
                DIFF_FILE_VALID(s) ? "valid" : "invalid",
                s->mode,
-               s->sha1_valid ? sha1_to_hex(s->sha1) : "");
+               s->oid_valid ? oid_to_hex(&s->oid) : "");
        fprintf(stderr, "queue[%d] %s size %lu\n",
                x, one ? one : "",
                s->size);
@@ -4284,11 +4424,11 @@ static void diff_resolve_rename_copy(void)
                        else
                                p->status = DIFF_STATUS_RENAMED;
                }
-               else if (hashcmp(p->one->sha1, p->two->sha1) ||
+               else if (oidcmp(&p->one->oid, &p->two->oid) ||
                         p->one->mode != p->two->mode ||
                         p->one->dirty_submodule ||
                         p->two->dirty_submodule ||
-                        is_null_sha1(p->one->sha1))
+                        is_null_oid(&p->one->oid))
                        p->status = DIFF_STATUS_MODIFIED;
                else {
                        /* This is a "no-change" entry and should not
@@ -4327,6 +4467,7 @@ static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
                name_a = p->two->path;
                name_b = NULL;
                strip_prefix(opt->prefix_length, &name_a, &name_b);
+               fprintf(opt->file, "%s", diff_line_prefix(opt));
                write_name_quoted(name_a, opt->file, opt->line_termination);
        }
 }
@@ -4429,14 +4570,26 @@ static void patch_id_consume(void *priv, char *line, unsigned long len)
        data->patchlen += new_len;
 }
 
+static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
+{
+       git_SHA1_Update(ctx, str, strlen(str));
+}
+
+static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
+{
+       /* large enough for 2^32 in octal */
+       char buf[12];
+       int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
+       git_SHA1_Update(ctx, buf, len);
+}
+
 /* returns 0 upon success, and writes result into sha1 */
-static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
+static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
        int i;
        git_SHA_CTX ctx;
        struct patch_id_t data;
-       char buffer[PATH_MAX * 4 + 20];
 
        git_SHA1_Init(&ctx);
        memset(&data, 0, sizeof(struct patch_id_t));
@@ -4465,47 +4618,47 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
 
                diff_fill_sha1_info(p->one);
                diff_fill_sha1_info(p->two);
-               if (fill_mmfile(&mf1, p->one) < 0 ||
-                               fill_mmfile(&mf2, p->two) < 0)
-                       return error("unable to read files to diff");
 
                len1 = remove_space(p->one->path, strlen(p->one->path));
                len2 = remove_space(p->two->path, strlen(p->two->path));
-               if (p->one->mode == 0)
-                       len1 = snprintf(buffer, sizeof(buffer),
-                                       "diff--gita/%.*sb/%.*s"
-                                       "newfilemode%06o"
-                                       "---/dev/null"
-                                       "+++b/%.*s",
-                                       len1, p->one->path,
-                                       len2, p->two->path,
-                                       p->two->mode,
-                                       len2, p->two->path);
-               else if (p->two->mode == 0)
-                       len1 = snprintf(buffer, sizeof(buffer),
-                                       "diff--gita/%.*sb/%.*s"
-                                       "deletedfilemode%06o"
-                                       "---a/%.*s"
-                                       "+++/dev/null",
-                                       len1, p->one->path,
-                                       len2, p->two->path,
-                                       p->one->mode,
-                                       len1, p->one->path);
-               else
-                       len1 = snprintf(buffer, sizeof(buffer),
-                                       "diff--gita/%.*sb/%.*s"
-                                       "---a/%.*s"
-                                       "+++b/%.*s",
-                                       len1, p->one->path,
-                                       len2, p->two->path,
-                                       len1, p->one->path,
-                                       len2, p->two->path);
-               git_SHA1_Update(&ctx, buffer, len1);
+               patch_id_add_string(&ctx, "diff--git");
+               patch_id_add_string(&ctx, "a/");
+               git_SHA1_Update(&ctx, p->one->path, len1);
+               patch_id_add_string(&ctx, "b/");
+               git_SHA1_Update(&ctx, p->two->path, len2);
+
+               if (p->one->mode == 0) {
+                       patch_id_add_string(&ctx, "newfilemode");
+                       patch_id_add_mode(&ctx, p->two->mode);
+                       patch_id_add_string(&ctx, "---/dev/null");
+                       patch_id_add_string(&ctx, "+++b/");
+                       git_SHA1_Update(&ctx, p->two->path, len2);
+               } else if (p->two->mode == 0) {
+                       patch_id_add_string(&ctx, "deletedfilemode");
+                       patch_id_add_mode(&ctx, p->one->mode);
+                       patch_id_add_string(&ctx, "---a/");
+                       git_SHA1_Update(&ctx, p->one->path, len1);
+                       patch_id_add_string(&ctx, "+++/dev/null");
+               } else {
+                       patch_id_add_string(&ctx, "---a/");
+                       git_SHA1_Update(&ctx, p->one->path, len1);
+                       patch_id_add_string(&ctx, "+++b/");
+                       git_SHA1_Update(&ctx, p->two->path, len2);
+               }
+
+               if (diff_header_only)
+                       continue;
+
+               if (fill_mmfile(&mf1, p->one) < 0 ||
+                   fill_mmfile(&mf2, p->two) < 0)
+                       return error("unable to read files to diff");
 
                if (diff_filespec_is_binary(p->one) ||
                    diff_filespec_is_binary(p->two)) {
-                       git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
-                       git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
+                       git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
+                                       40);
+                       git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
+                                       40);
                        continue;
                }
 
@@ -4522,11 +4675,11 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
        return 0;
 }
 
-int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
+int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
        int i;
-       int result = diff_get_patch_id(options, sha1);
+       int result = diff_get_patch_id(options, sha1, diff_header_only);
 
        for (i = 0; i < q->nr; i++)
                diff_free_filepair(q->queue[i]);
@@ -4563,25 +4716,25 @@ static int is_summary_empty(const struct diff_queue_struct *q)
 }
 
 static const char rename_limit_warning[] =
-"inexact rename detection was skipped due to too many files.";
+N_("inexact rename detection was skipped due to too many files.");
 
 static const char degrade_cc_to_c_warning[] =
-"only found copies from modified paths due to too many files.";
+N_("only found copies from modified paths due to too many files.");
 
 static const char rename_limit_advice[] =
-"you may want to set your %s variable to at least "
-"%d and retry the command.";
+N_("you may want to set your %s variable to at least "
+   "%d and retry the command.");
 
 void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
 {
        if (degraded_cc)
-               warning(degrade_cc_to_c_warning);
+               warning(_(degrade_cc_to_c_warning));
        else if (needed)
-               warning(rename_limit_warning);
+               warning(_(rename_limit_warning));
        else
                return;
        if (0 < needed && needed < 32767)
-               warning(rename_limit_advice, varname, needed);
+               warning(_(rename_limit_advice), varname, needed);
 }
 
 void diff_flush(struct diff_options *options)
@@ -4797,7 +4950,7 @@ static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
         */
        if (!DIFF_FILE_VALID(p->one) || /* (1) */
            !DIFF_FILE_VALID(p->two) ||
-           (p->one->sha1_valid && p->two->sha1_valid) ||
+           (p->one->oid_valid && p->two->oid_valid) ||
            (p->one->mode != p->two->mode) ||
            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
@@ -4848,7 +5001,7 @@ static int diffnamecmp(const void *a_, const void *b_)
 void diffcore_fix_diff_index(struct diff_options *options)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
-       qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
+       QSORT(q->queue, q->nr, diffnamecmp);
 }
 
 void diffcore_std(struct diff_options *options)
@@ -4988,14 +5141,10 @@ void diff_change(struct diff_options *options,
                return;
 
        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
-               unsigned tmp;
-               const unsigned char *tmp_c;
-               tmp = old_mode; old_mode = new_mode; new_mode = tmp;
-               tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
-               tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
-                       new_sha1_valid = tmp;
-               tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
-                       new_dirty_submodule = tmp;
+               SWAP(old_mode, new_mode);
+               SWAP(old_sha1, new_sha1);
+               SWAP(old_sha1_valid, new_sha1_valid);
+               SWAP(old_dirty_submodule, new_dirty_submodule);
        }
 
        if (options->prefix &&
@@ -5079,7 +5228,7 @@ size_t fill_textconv(struct userdiff_driver *driver,
 {
        size_t size;
 
-       if (!driver || !driver->textconv) {
+       if (!driver) {
                if (!DIFF_FILE_VALID(df)) {
                        *outbuf = "";
                        return 0;
@@ -5090,8 +5239,12 @@ size_t fill_textconv(struct userdiff_driver *driver,
                return df->size;
        }
 
-       if (driver->textconv_cache && df->sha1_valid) {
-               *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
+       if (!driver->textconv)
+               die("BUG: fill_textconv called with non-textconv driver");
+
+       if (driver->textconv_cache && df->oid_valid) {
+               *outbuf = notes_cache_get(driver->textconv_cache,
+                                         df->oid.hash,
                                          &size);
                if (*outbuf)
                        return size;
@@ -5101,9 +5254,9 @@ size_t fill_textconv(struct userdiff_driver *driver,
        if (!*outbuf)
                die("unable to read files to diff");
 
-       if (driver->textconv_cache && df->sha1_valid) {
+       if (driver->textconv_cache && df->oid_valid) {
                /* ignore errors, as we might be in a readonly repository */
-               notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
+               notes_cache_put(driver->textconv_cache, df->oid.hash, *outbuf,
                                size);
                /*
                 * we could save up changes and flush them all at the end,