Changed fast-import's pack header creation to use pack.h
[gitweb.git] / builtin-apply.c
index e9ead002d38368f6de6ba75f25542fe61258cfb9..4f0eef0ac3c2d20475b0b50e81f4d51cd4f95396 100644 (file)
 #include "delta.h"
 #include "builtin.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.
-//
+/*
+ *  --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 p_value = 1;
-static int allow_binary_replacement = 0;
-static int check_index = 0;
-static int write_index = 0;
-static int cached = 0;
-static int diffstat = 0;
-static int numstat = 0;
-static int summary = 0;
-static int check = 0;
+static int allow_binary_replacement;
+static int check_index;
+static int write_index;
+static int cached;
+static int diffstat;
+static int numstat;
+static int summary;
+static int check;
 static int apply = 1;
-static int no_add = 0;
-static int show_index_info = 0;
+static int apply_in_reverse;
+static int no_add;
+static int show_index_info;
 static int line_termination = '\n';
 static unsigned long p_context = -1;
 static const char apply_usage[] =
@@ -49,10 +51,10 @@ static enum whitespace_eol {
        error_on_whitespace,
        strip_whitespace,
 } new_whitespace = warn_on_whitespace;
-static int whitespace_error = 0;
+static int whitespace_error;
 static int squelch_whitespace_errors = 5;
-static int applied_after_stripping = 0;
-static const char *patch_input_file = NULL;
+static int applied_after_stripping;
+static const char *patch_input_file;
 
 static void parse_whitespace_option(const char *option)
 {
@@ -107,6 +109,13 @@ static int max_change, max_len;
  */
 static int linenr = 1;
 
+/*
+ * This represents one "hunk" from a patch, starting with
+ * "@@ -oldpos,oldlines +newpos,newlines @@" marker.  The
+ * patch text is pointed at by patch, and its byte length
+ * is stored in size.  leading and trailing are the number
+ * of context lines.
+ */
 struct fragment {
        unsigned long leading, trailing;
        unsigned long oldpos, oldlines;
@@ -116,12 +125,19 @@ struct fragment {
        struct fragment *next;
 };
 
+/*
+ * When dealing with a binary patch, we reuse "leading" field
+ * to store the type of the binary hunk, either deflated "delta"
+ * or deflated "literal".
+ */
+#define binary_patch_method leading
+#define BINARY_DELTA_DEFLATED  1
+#define BINARY_LITERAL_DEFLATED 2
+
 struct patch {
        char *new_name, *old_name, *def_name;
        unsigned int old_mode, new_mode;
        int is_rename, is_copy, is_new, is_delete, is_binary;
-#define BINARY_DELTA_DEFLATED 1
-#define BINARY_LITERAL_DEFLATED 2
        unsigned long deflate_origlen;
        int lines_added, lines_deleted;
        int score;
@@ -284,8 +300,8 @@ static void parse_traditional_patch(const char *first, const char *second, struc
 {
        char *name;
 
-       first += 4;     // skip "--- "
-       second += 4;    // skip "+++ "
+       first += 4;     /* skip "--- " */
+       second += 4;    /* skip "+++ " */
        if (is_dev_null(first)) {
                patch->is_new = 1;
                patch->is_delete = 0;
@@ -765,7 +781,7 @@ static int find_header(char *line, unsigned long size, int *hdrsize, struct patc
                        continue;
 
                /*
-                * Make sure we don't find any unconnected patch fragmants.
+                * Make sure we don't find any unconnected patch fragments.
                 * That's a sign that we didn't find a header, and that a
                 * patch has become corrupted/broken up.
                 */
@@ -977,43 +993,70 @@ static inline int metadata_changes(struct patch *patch)
                 patch->old_mode != patch->new_mode);
 }
 
-static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
+static char *inflate_it(const void *data, unsigned long size,
+                       unsigned long inflated_size)
 {
-       /* We have read "GIT binary patch\n"; what follows is a line
-        * that says the patch method (currently, either "deflated
-        * literal" or "deflated delta") and the length of data before
-        * deflating; a sequence of 'length-byte' followed by base-85
-        * encoded data follows.
+       z_stream stream;
+       void *out;
+       int st;
+
+       memset(&stream, 0, sizeof(stream));
+
+       stream.next_in = (unsigned char *)data;
+       stream.avail_in = size;
+       stream.next_out = out = xmalloc(inflated_size);
+       stream.avail_out = inflated_size;
+       inflateInit(&stream);
+       st = inflate(&stream, Z_FINISH);
+       if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
+               free(out);
+               return NULL;
+       }
+       return out;
+}
+
+static struct fragment *parse_binary_hunk(char **buf_p,
+                                         unsigned long *sz_p,
+                                         int *status_p,
+                                         int *used_p)
+{
+       /* Expect a line that begins with binary patch method ("literal"
+        * or "delta"), followed by the length of data before deflating.
+        * a sequence of 'length-byte' followed by base-85 encoded data
+        * should follow, terminated by a newline.
         *
         * Each 5-byte sequence of base-85 encodes up to 4 bytes,
         * and we would limit the patch line to 66 characters,
         * so one line can fit up to 13 groups that would decode
         * to 52 bytes max.  The length byte 'A'-'Z' corresponds
         * to 1-26 bytes, and 'a'-'z' corresponds to 27-52 bytes.
-        * The end of binary is signalled with an empty line.
         */
        int llen, used;
-       struct fragment *fragment;
+       unsigned long size = *sz_p;
+       char *buffer = *buf_p;
+       int patch_method;
+       unsigned long origlen;
        char *data = NULL;
+       int hunk_size = 0;
+       struct fragment *frag;
 
-       patch->fragments = fragment = xcalloc(1, sizeof(*fragment));
-
-       /* Grab the type of patch */
        llen = linelen(buffer, size);
        used = llen;
-       linenr++;
+
+       *status_p = 0;
 
        if (!strncmp(buffer, "delta ", 6)) {
-               patch->is_binary = BINARY_DELTA_DEFLATED;
-               patch->deflate_origlen = strtoul(buffer + 6, NULL, 10);
+               patch_method = BINARY_DELTA_DEFLATED;
+               origlen = strtoul(buffer + 6, NULL, 10);
        }
        else if (!strncmp(buffer, "literal ", 8)) {
-               patch->is_binary = BINARY_LITERAL_DEFLATED;
-               patch->deflate_origlen = strtoul(buffer + 8, NULL, 10);
+               patch_method = BINARY_LITERAL_DEFLATED;
+               origlen = strtoul(buffer + 8, NULL, 10);
        }
        else
-               return error("unrecognized binary patch at line %d: %.*s",
-                            linenr-1, llen-1, buffer);
+               return NULL;
+
+       linenr++;
        buffer += llen;
        while (1) {
                int byte_length, max_byte_length, newsize;
@@ -1042,21 +1085,79 @@ static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
                if (max_byte_length < byte_length ||
                    byte_length <= max_byte_length - 4)
                        goto corrupt;
-               newsize = fragment->size + byte_length;
+               newsize = hunk_size + byte_length;
                data = xrealloc(data, newsize);
-               if (decode_85(data + fragment->size,
-                             buffer + 1,
-                             byte_length))
+               if (decode_85(data + hunk_size, buffer + 1, byte_length))
                        goto corrupt;
-               fragment->size = newsize;
+               hunk_size = newsize;
                buffer += llen;
                size -= llen;
        }
-       fragment->patch = data;
-       return used;
+
+       frag = xcalloc(1, sizeof(*frag));
+       frag->patch = inflate_it(data, hunk_size, origlen);
+       if (!frag->patch)
+               goto corrupt;
+       free(data);
+       frag->size = origlen;
+       *buf_p = buffer;
+       *sz_p = size;
+       *used_p = used;
+       frag->binary_patch_method = patch_method;
+       return frag;
+
  corrupt:
-       return error("corrupt binary patch at line %d: %.*s",
-                    linenr-1, llen-1, buffer);
+       if (data)
+               free(data);
+       *status_p = -1;
+       error("corrupt binary patch at line %d: %.*s",
+             linenr-1, llen-1, buffer);
+       return NULL;
+}
+
+static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
+{
+       /* We have read "GIT binary patch\n"; what follows is a line
+        * that says the patch method (currently, either "literal" or
+        * "delta") and the length of data before deflating; a
+        * sequence of 'length-byte' followed by base-85 encoded data
+        * follows.
+        *
+        * When a binary patch is reversible, there is another binary
+        * hunk in the same format, starting with patch method (either
+        * "literal" or "delta") with the length of data, and a sequence
+        * of length-byte + base-85 encoded data, terminated with another
+        * empty line.  This data, when applied to the postimage, produces
+        * the preimage.
+        */
+       struct fragment *forward;
+       struct fragment *reverse;
+       int status;
+       int used, used_1;
+
+       forward = parse_binary_hunk(&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);
+       if (status)
+               /* otherwise we already gave an error message */
+               return status;
+
+       reverse = parse_binary_hunk(&buffer, &size, &status, &used_1);
+       if (reverse)
+               used += used_1;
+       else if (status) {
+               /* not having reverse hunk is not an error, but having
+                * a corrupt reverse hunk is.
+                */
+               free((void*) forward->patch);
+               free(forward);
+               return status;
+       }
+       forward->next = reverse;
+       patch->fragments = forward;
+       patch->is_binary = 1;
+       return used;
 }
 
 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
@@ -1118,6 +1219,33 @@ static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
        return offset + hdrsize + patchsize;
 }
 
+#define swap(a,b) myswap((a),(b),sizeof(a))
+
+#define myswap(a, b, size) do {                \
+       unsigned char mytmp[size];      \
+       memcpy(mytmp, &a, size);                \
+       memcpy(&a, &b, size);           \
+       memcpy(&b, mytmp, size);                \
+} while (0)
+
+static void reverse_patches(struct patch *p)
+{
+       for (; p; p = p->next) {
+               struct fragment *frag = p->fragments;
+
+               swap(p->new_name, p->old_name);
+               swap(p->new_mode, p->old_mode);
+               swap(p->is_new, p->is_delete);
+               swap(p->lines_added, p->lines_deleted);
+               swap(p->old_sha1_prefix, p->new_sha1_prefix);
+
+               for (; frag; frag = frag->next) {
+                       swap(frag->newpos, frag->oldpos);
+                       swap(frag->newlines, frag->oldlines);
+               }
+       }
+}
+
 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 static const char minuses[]= "----------------------------------------------------------------------";
 
@@ -1334,8 +1462,7 @@ static int apply_line(char *output, const char *patch, int plen)
        return plen;
 }
 
-static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag,
-       int inaccurate_eof)
+static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag, int inaccurate_eof)
 {
        int match_beginning, match_end;
        char *buf = desc->buffer;
@@ -1349,6 +1476,7 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag,
        int pos, lines;
 
        while (size > 0) {
+               char first;
                int len = linelen(patch, size);
                int plen;
 
@@ -1365,16 +1493,23 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag,
                plen = len-1;
                if (len < size && patch[len] == '\\')
                        plen--;
-               switch (*patch) {
+               first = *patch;
+               if (apply_in_reverse) {
+                       if (first == '-')
+                               first = '+';
+                       else if (first == '+')
+                               first = '-';
+               }
+               switch (first) {
                case ' ':
                case '-':
                        memcpy(old + oldsize, patch + 1, plen);
                        oldsize += plen;
-                       if (*patch == '-')
+                       if (first == '-')
                                break;
                /* Fall-through for ' ' */
                case '+':
-                       if (*patch != '+' || !no_add)
+                       if (first != '+' || !no_add)
                                newsize += apply_line(new + newsize, patch,
                                                      plen);
                        break;
@@ -1469,28 +1604,6 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag,
        return offset;
 }
 
-static char *inflate_it(const void *data, unsigned long size,
-                       unsigned long inflated_size)
-{
-       z_stream stream;
-       void *out;
-       int st;
-
-       memset(&stream, 0, sizeof(stream));
-
-       stream.next_in = (unsigned char *)data;
-       stream.avail_in = size;
-       stream.next_out = out = xmalloc(inflated_size);
-       stream.avail_out = inflated_size;
-       inflateInit(&stream);
-       st = inflate(&stream, Z_FINISH);
-       if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
-               free(out);
-               return NULL;
-       }
-       return out;
-}
-
 static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
 {
        unsigned long dst_size;
@@ -1498,24 +1611,29 @@ static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
        void *data;
        void *result;
 
-       data = inflate_it(fragment->patch, fragment->size,
-                         patch->deflate_origlen);
-       if (!data)
-               return error("corrupt patch data");
-       switch (patch->is_binary) {
+       /* Binary patch is irreversible without the optional second hunk */
+       if (apply_in_reverse) {
+               if (!fragment->next)
+                       return error("cannot reverse-apply a binary patch "
+                                    "without the reverse hunk to '%s'",
+                                    patch->new_name
+                                    ? patch->new_name : patch->old_name);
+               fragment = fragment;
+       }
+       data = (void*) fragment->patch;
+       switch (fragment->binary_patch_method) {
        case BINARY_DELTA_DEFLATED:
                result = patch_delta(desc->buffer, desc->size,
                                     data,
-                                    patch->deflate_origlen,
+                                    fragment->size,
                                     &dst_size);
                free(desc->buffer);
                desc->buffer = result;
-               free(data);
                break;
        case BINARY_LITERAL_DEFLATED:
                free(desc->buffer);
                desc->buffer = data;
-               dst_size = patch->deflate_origlen;
+               dst_size = fragment->size;
                break;
        }
        if (!desc->buffer)
@@ -1566,7 +1684,7 @@ static int apply_binary(struct buffer_desc *desc, struct patch *patch)
        }
 
        get_sha1_hex(patch->new_sha1_prefix, sha1);
-       if (!memcmp(sha1, null_sha1, 20)) {
+       if (is_null_sha1(sha1)) {
                free(desc->buffer);
                desc->alloc = desc->size = 0;
                desc->buffer = NULL;
@@ -1654,6 +1772,12 @@ static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *
        desc.buffer = buf;
        if (apply_fragments(&desc, patch) < 0)
                return -1;
+
+       /* NUL terminate the result */
+       if (desc.alloc <= desc.size)
+               desc.buffer = xrealloc(desc.buffer, desc.size + 1);
+       desc.buffer[desc.size] = 0;
+
        patch->result = desc.buffer;
        patch->resultsize = desc.size;
 
@@ -1663,13 +1787,14 @@ static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *
        return 0;
 }
 
-static int check_patch(struct patch *patch)
+static int check_patch(struct patch *patch, struct patch *prev_patch)
 {
        struct stat st;
        const char *old_name = patch->old_name;
        const char *new_name = patch->new_name;
        const char *name = old_name ? old_name : new_name;
        struct cache_entry *ce = NULL;
+       int ok_if_exists;
 
        if (old_name) {
                int changed = 0;
@@ -1727,13 +1852,33 @@ static int check_patch(struct patch *patch)
                                old_name, st_mode, patch->old_mode);
        }
 
+       if (new_name && prev_patch && prev_patch->is_delete &&
+           !strcmp(prev_patch->old_name, new_name))
+               /* A type-change diff is always split into a patch to
+                * delete old, immediately followed by a patch to
+                * create new (see diff.c::run_diff()); in such a case
+                * it is Ok that the entry to be deleted by the
+                * previous patch is still in the working tree and in
+                * the index.
+                */
+               ok_if_exists = 1;
+       else
+               ok_if_exists = 0;
+
        if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
-               if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
+               if (check_index &&
+                   cache_name_pos(new_name, strlen(new_name)) >= 0 &&
+                   !ok_if_exists)
                        return error("%s: already exists in index", new_name);
                if (!cached) {
-                       if (!lstat(new_name, &st))
-                               return error("%s: already exists in working directory", new_name);
-                       if (errno != ENOENT)
+                       struct stat nst;
+                       if (!lstat(new_name, &nst)) {
+                               if (S_ISDIR(nst.st_mode) || ok_if_exists)
+                                       ; /* ok */
+                               else
+                                       return error("%s: already exists in working directory", new_name);
+                       }
+                       else if ((errno != ENOENT) && (errno != ENOTDIR))
                                return error("%s: %s", new_name, strerror(errno));
                }
                if (!patch->new_mode) {
@@ -1761,18 +1906,16 @@ static int check_patch(struct patch *patch)
 
 static int check_patch_list(struct patch *patch)
 {
+       struct patch *prev_patch = NULL;
        int error = 0;
 
-       for (;patch ; patch = patch->next)
-               error |= check_patch(patch);
+       for (prev_patch = NULL; patch ; patch = patch->next) {
+               error |= check_patch(patch, prev_patch);
+               prev_patch = patch;
+       }
        return error;
 }
 
-static inline int is_null_sha1(const unsigned char *sha1)
-{
-       return !memcmp(sha1, null_sha1, 20);
-}
-
 static void show_index_list(struct patch *list)
 {
        struct patch *patch;
@@ -1972,6 +2115,9 @@ static int try_create_file(const char *path, unsigned int mode, const char *buf,
        int fd;
 
        if (S_ISLNK(mode))
+               /* Although buf:size is counted string, it also is NUL
+                * terminated.
+                */
                return symlink(buf, path);
        fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
        if (fd < 0)
@@ -2009,6 +2155,16 @@ static void create_one_file(char *path, unsigned mode, const char *buf, unsigned
                        return;
        }
 
+       if (errno == EEXIST || errno == EACCES) {
+               /* We may be trying to create a file where a directory
+                * used to be.
+                */
+               struct stat st;
+               errno = 0;
+               if (!lstat(path, &st) && S_ISDIR(st.st_mode) && !rmdir(path))
+                       errno = EEXIST;
+       }
+
        if (errno == EEXIST) {
                unsigned int nr = getpid();
 
@@ -2043,32 +2199,42 @@ static void create_file(struct patch *patch)
        cache_tree_invalidate_path(active_cache_tree, path);
 }
 
-static void write_out_one_result(struct patch *patch)
+/* phase zero is to remove, phase one is to create */
+static void write_out_one_result(struct patch *patch, int phase)
 {
        if (patch->is_delete > 0) {
-               remove_file(patch);
+               if (phase == 0)
+                       remove_file(patch);
                return;
        }
        if (patch->is_new > 0 || patch->is_copy) {
-               create_file(patch);
+               if (phase == 1)
+                       create_file(patch);
                return;
        }
        /*
         * Rename or modification boils down to the same
         * thing: remove the old, write the new
         */
-       remove_file(patch);
+       if (phase == 0)
+               remove_file(patch);
+       if (phase == 1)
        create_file(patch);
 }
 
 static void write_out_results(struct patch *list, int skipped_patch)
 {
+       int phase;
+
        if (!list && !skipped_patch)
                die("No changes");
 
-       while (list) {
-               write_out_one_result(list);
-               list = list->next;
+       for (phase = 0; phase < 2; phase++) {
+               struct patch *l = list;
+               while (l) {
+                       write_out_one_result(l, phase);
+                       l = l->next;
+               }
        }
 }
 
@@ -2117,6 +2283,8 @@ static int apply_patch(int fd, const char *filename, int inaccurate_eof)
                nr = parse_chunk(buffer + offset, size, patch);
                if (nr < 0)
                        break;
+               if (apply_in_reverse)
+                       reverse_patches(patch);
                if (use_patch(patch)) {
                        patch_stats(patch);
                        *listp = patch;
@@ -2134,12 +2302,9 @@ static int apply_patch(int fd, const char *filename, int inaccurate_eof)
                apply = 0;
 
        write_index = check_index && apply;
-       if (write_index && newfd < 0) {
+       if (write_index && newfd < 0)
                newfd = hold_lock_file_for_update(&lock_file,
-                                                 get_index_file());
-               if (newfd < 0)
-                       die("unable to create new index file");
-       }
+                                                 get_index_file(), 1);
        if (check_index) {
                if (read_cache() < 0)
                        die("unable to read index file");
@@ -2177,7 +2342,7 @@ static int git_apply_config(const char *var, const char *value)
 }
 
 
-int cmd_apply(int argc, const char **argv, char **envp)
+int cmd_apply(int argc, const char **argv, const char *prefix)
 {
        int i;
        int read_stdin = 1;
@@ -2268,6 +2433,10 @@ int cmd_apply(int argc, const char **argv, char **envp)
                        parse_whitespace_option(arg + 13);
                        continue;
                }
+               if (!strcmp(arg, "-R") || !strcmp(arg, "--reverse")) {
+                       apply_in_reverse = 1;
+                       continue;
+               }
                if (!strcmp(arg, "--inaccurate-eof")) {
                        inaccurate_eof = 1;
                        continue;
@@ -2323,7 +2492,7 @@ int cmd_apply(int argc, const char **argv, char **envp)
 
        if (write_index) {
                if (write_cache(newfd, active_cache, active_nr) ||
-                   commit_lock_file(&lock_file))
+                   close(newfd) || commit_lock_file(&lock_file))
                        die("Unable to write new index file");
        }