Merge branch 'jc/grep'
[gitweb.git] / apply.c
diff --git a/apply.c b/apply.c
index c50b3a60464ea05307af8e8d1be576cf96415ff0..7c8146a7f317d9d1743e6a780eec823be72905a6 100644 (file)
--- a/apply.c
+++ b/apply.c
@@ -9,6 +9,8 @@
 #include <fnmatch.h>
 #include "cache.h"
 #include "quote.h"
+#include "blob.h"
+#include "delta.h"
 
 //  --check turns on checking that the working tree matches the
 //    files that are being modified, but doesn't apply the patch
@@ -18,6 +20,7 @@
 //
 static const char *prefix;
 static int prefix_length = -1;
+static int newfd = -1;
 
 static int p_value = 1;
 static int allow_binary_replacement = 0;
@@ -31,8 +34,9 @@ static int apply = 1;
 static int no_add = 0;
 static int show_index_info = 0;
 static int line_termination = '\n';
+static unsigned long p_context = -1;
 static const char apply_usage[] =
-"git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] [-pNUM] [--whitespace=<nowarn|warn|error|error-all|strip>] <patch>...";
+"git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] [-pNUM] [-CNUM] [--whitespace=<nowarn|warn|error|error-all|strip>] <patch>...";
 
 static enum whitespace_eol {
        nowarn_whitespace,
@@ -99,6 +103,7 @@ static int max_change, max_len;
 static int linenr = 1;
 
 struct fragment {
+       unsigned long leading, trailing;
        unsigned long oldpos, oldlines;
        unsigned long newpos, newlines;
        const char *patch;
@@ -110,6 +115,9 @@ 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;
        struct fragment *fragments;
@@ -816,12 +824,15 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
        int added, deleted;
        int len = linelen(line, size), offset;
        unsigned long oldlines, newlines;
+       unsigned long leading, trailing;
 
        offset = parse_fragment_header(line, len, fragment);
        if (offset < 0)
                return -1;
        oldlines = fragment->oldlines;
        newlines = fragment->newlines;
+       leading = 0;
+       trailing = 0;
 
        if (patch->is_new < 0) {
                patch->is_new =  !oldlines;
@@ -859,10 +870,14 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
                case ' ':
                        oldlines--;
                        newlines--;
+                       if (!deleted && !added)
+                               leading++;
+                       trailing++;
                        break;
                case '-':
                        deleted++;
                        oldlines--;
+                       trailing = 0;
                        break;
                case '+':
                        /*
@@ -886,6 +901,7 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
                        }
                        added++;
                        newlines--;
+                       trailing = 0;
                        break;
 
                 /* We allow "\ No newline at end of file". Depending
@@ -903,6 +919,9 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
        }
        if (oldlines || newlines)
                return -1;
+       fragment->leading = leading;
+       fragment->trailing = trailing;
+
        /* If a fragment ends with an incomplete line, we failed to include
         * it in the above loop because we hit oldlines == newlines == 0
         * before seeing it.
@@ -924,8 +943,7 @@ static int parse_single_patch(char *line, unsigned long size, struct patch *patc
                struct fragment *fragment;
                int len;
 
-               fragment = xmalloc(sizeof(*fragment));
-               memset(fragment, 0, sizeof(*fragment));
+               fragment = xcalloc(1, sizeof(*fragment));
                len = parse_fragment(line, size, patch, fragment);
                if (len <= 0)
                        die("corrupt patch at line %d", linenr);
@@ -953,6 +971,88 @@ 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)
+{
+       /* 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.
+        *
+        * 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;
+       char *data = NULL;
+
+       patch->fragments = fragment = xcalloc(1, sizeof(*fragment));
+
+       /* Grab the type of patch */
+       llen = linelen(buffer, size);
+       used = llen;
+       linenr++;
+
+       if (!strncmp(buffer, "delta ", 6)) {
+               patch->is_binary = BINARY_DELTA_DEFLATED;
+               patch->deflate_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);
+       }
+       else
+               return error("unrecognized binary patch at line %d: %.*s",
+                            linenr-1, llen-1, buffer);
+       buffer += llen;
+       while (1) {
+               int byte_length, max_byte_length, newsize;
+               llen = linelen(buffer, size);
+               used += llen;
+               linenr++;
+               if (llen == 1)
+                       break;
+               /* Minimum line is "A00000\n" which is 7-byte long,
+                * and the line length must be multiple of 5 plus 2.
+                */
+               if ((llen < 7) || (llen-2) % 5)
+                       goto corrupt;
+               max_byte_length = (llen - 2) / 5 * 4;
+               byte_length = *buffer;
+               if ('A' <= byte_length && byte_length <= 'Z')
+                       byte_length = byte_length - 'A' + 1;
+               else if ('a' <= byte_length && byte_length <= 'z')
+                       byte_length = byte_length - 'a' + 27;
+               else
+                       goto corrupt;
+               /* if the input length was not multiple of 4, we would
+                * have filler at the end but the filler should never
+                * exceed 3 bytes
+                */
+               if (max_byte_length < byte_length ||
+                   byte_length <= max_byte_length - 4)
+                       goto corrupt;
+               newsize = fragment->size + byte_length;
+               data = xrealloc(data, newsize);
+               if (decode_85(data + fragment->size,
+                             buffer + 1,
+                             byte_length))
+                       goto corrupt;
+               fragment->size = newsize;
+               buffer += llen;
+               size -= llen;
+       }
+       fragment->patch = data;
+       return used;
+ corrupt:
+       return error("corrupt binary patch at line %d: %.*s",
+                    linenr-1, llen-1, buffer);
+}
+
 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
 {
        int hdrsize, patchsize;
@@ -969,19 +1069,34 @@ static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
                        "Files ",
                        NULL,
                };
+               static const char git_binary[] = "GIT binary patch\n";
                int i;
                int hd = hdrsize + offset;
                unsigned long llen = linelen(buffer + hd, size - hd);
 
-               if (!memcmp(" differ\n", buffer + hd + llen - 8, 8))
+               if (llen == sizeof(git_binary) - 1 &&
+                   !memcmp(git_binary, buffer + hd, llen)) {
+                       int used;
+                       linenr++;
+                       used = parse_binary(buffer + hd + llen,
+                                           size - hd - llen, patch);
+                       if (used)
+                               patchsize = used + llen;
+                       else
+                               patchsize = 0;
+               }
+               else if (!memcmp(" differ\n", buffer + hd + llen - 8, 8)) {
                        for (i = 0; binhdr[i]; i++) {
                                int len = strlen(binhdr[i]);
                                if (len < size - hd &&
                                    !memcmp(binhdr[i], buffer + hd, len)) {
+                                       linenr++;
                                        patch->is_binary = 1;
+                                       patchsize = llen;
                                        break;
                                }
                        }
+               }
 
                /* Empty patch cannot be applied if:
                 * - it is a binary patch and we do not do binary_replace, or
@@ -1087,7 +1202,7 @@ static int read_old_data(struct stat *st, const char *path, void *buf, unsigned
        }
 }
 
-static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line)
+static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line, int *lines)
 {
        int i;
        unsigned long start, backwards, forwards;
@@ -1148,6 +1263,7 @@ static int find_offset(const char *buf, unsigned long size, const char *fragment
                n = (i >> 1)+1;
                if (i & 1)
                        n = -n;
+               *lines = n;
                return try;
        }
 
@@ -1157,6 +1273,33 @@ static int find_offset(const char *buf, unsigned long size, const char *fragment
        return -1;
 }
 
+static void remove_first_line(const char **rbuf, int *rsize)
+{
+       const char *buf = *rbuf;
+       int size = *rsize;
+       unsigned long offset;
+       offset = 0;
+       while (offset <= size) {
+               if (buf[offset++] == '\n')
+                       break;
+       }
+       *rsize = size - offset;
+       *rbuf = buf + offset;
+}
+
+static void remove_last_line(const char **rbuf, int *rsize)
+{
+       const char *buf = *rbuf;
+       int size = *rsize;
+       unsigned long offset;
+       offset = size - 1;
+       while (offset > 0) {
+               if (buf[--offset] == '\n')
+                       break;
+       }
+       *rsize = offset + 1;
+}
+
 struct buffer_desc {
        char *buffer;
        unsigned long size;
@@ -1192,7 +1335,10 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
        int offset, size = frag->size;
        char *old = xmalloc(size);
        char *new = xmalloc(size);
+       const char *oldlines, *newlines;
        int oldsize = 0, newsize = 0;
+       unsigned long leading, trailing;
+       int pos, lines;
 
        while (size > 0) {
                int len = linelen(patch, size);
@@ -1241,23 +1387,59 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
                newsize--;
        }
 #endif
-                       
-       offset = find_offset(buf, desc->size, old, oldsize, frag->newpos);
-       if (offset >= 0) {
-               int diff = newsize - oldsize;
-               unsigned long size = desc->size + diff;
-               unsigned long alloc = desc->alloc;
-
-               if (size > alloc) {
-                       alloc = size + 8192;
-                       desc->alloc = alloc;
-                       buf = xrealloc(buf, alloc);
-                       desc->buffer = buf;
+
+       oldlines = old;
+       newlines = new;
+       leading = frag->leading;
+       trailing = frag->trailing;
+       lines = 0;
+       pos = frag->newpos;
+       for (;;) {
+               offset = find_offset(buf, desc->size, oldlines, oldsize, pos, &lines);
+               if (offset >= 0) {
+                       int diff = newsize - oldsize;
+                       unsigned long size = desc->size + diff;
+                       unsigned long alloc = desc->alloc;
+
+                       /* Warn if it was necessary to reduce the number
+                        * of context lines.
+                        */
+                       if ((leading != frag->leading) || (trailing != frag->trailing))
+                               fprintf(stderr, "Context reduced to (%ld/%ld) to apply fragment at %d\n",
+                                       leading, trailing, pos + lines);
+
+                       if (size > alloc) {
+                               alloc = size + 8192;
+                               desc->alloc = alloc;
+                               buf = xrealloc(buf, alloc);
+                               desc->buffer = buf;
+                       }
+                       desc->size = size;
+                       memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
+                       memcpy(buf + offset, newlines, newsize);
+                       offset = 0;
+
+                       break;
+               }
+
+               /* Am I at my context limits? */
+               if ((leading <= p_context) && (trailing <= p_context))
+                       break;
+               /* Reduce the number of context lines
+                * Reduce both leading and trailing if they are equal
+                * otherwise just reduce the larger context.
+                */
+               if (leading >= trailing) {
+                       remove_first_line(&oldlines, &oldsize);
+                       remove_first_line(&newlines, &newsize);
+                       pos--;
+                       leading--;
+               }
+               if (trailing > leading) {
+                       remove_last_line(&oldlines, &oldsize);
+                       remove_last_line(&newlines, &newsize);
+                       trailing--;
                }
-               desc->size = size;
-               memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
-               memcpy(buf + offset, new, newsize);
-               offset = 0;
        }
 
        free(old);
@@ -1265,76 +1447,150 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
        return offset;
 }
 
-static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
+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;
+       struct fragment *fragment = patch->fragments;
+       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) {
+       case BINARY_DELTA_DEFLATED:
+               result = patch_delta(desc->buffer, desc->size,
+                                    data,
+                                    patch->deflate_origlen,
+                                    &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;
+               break;
+       }
+       if (!desc->buffer)
+               return -1;
+       desc->size = desc->alloc = dst_size;
+       return 0;
+}
+
+static int apply_binary(struct buffer_desc *desc, struct patch *patch)
 {
-       struct fragment *frag = patch->fragments;
        const char *name = patch->old_name ? patch->old_name : patch->new_name;
+       unsigned char sha1[20];
+       unsigned char hdr[50];
+       int hdrlen;
 
-       if (patch->is_binary) {
-               unsigned char sha1[20];
+       if (!allow_binary_replacement)
+               return error("cannot apply binary patch to '%s' "
+                            "without --allow-binary-replacement",
+                            name);
 
-               if (!allow_binary_replacement)
-                       return error("cannot apply binary patch to '%s' "
-                                    "without --allow-binary-replacement",
-                                    name);
+       /* 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))
+               return error("cannot apply binary patch to '%s' "
+                            "without full index line", name);
 
-               /* For safety, we require patch index line to contain
-                * full 40-byte textual SHA1 for old and new, at least for now.
+       if (patch->old_name) {
+               /* See if the old one matches what the patch
+                * applies to.
                 */
-               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))
-                       return error("cannot apply binary patch to '%s' "
-                                    "without full index line", name);
-
-               if (patch->old_name) {
-                       unsigned char hdr[50];
-                       int hdrlen;
-
-                       /* See if the old one matches what the patch
-                        * applies to.
-                        */
-                       write_sha1_file_prepare(desc->buffer, desc->size,
-                                               "blob", sha1, hdr, &hdrlen);
-                       if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
-                               return error("the patch applies to '%s' (%s), "
-                                            "which does not match the "
-                                            "current contents.",
-                                            name, sha1_to_hex(sha1));
-               }
-               else {
-                       /* Otherwise, the old one must be empty. */
-                       if (desc->size)
-                               return error("the patch applies to an empty "
-                                            "'%s' but it is not empty", name);
-               }
+               write_sha1_file_prepare(desc->buffer, desc->size,
+                                       blob_type, sha1, hdr, &hdrlen);
+               if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
+                       return error("the patch applies to '%s' (%s), "
+                                    "which does not match the "
+                                    "current contents.",
+                                    name, sha1_to_hex(sha1));
+       }
+       else {
+               /* Otherwise, the old one must be empty. */
+               if (desc->size)
+                       return error("the patch applies to an empty "
+                                    "'%s' but it is not empty", name);
+       }
+
+       get_sha1_hex(patch->new_sha1_prefix, sha1);
+       if (!memcmp(sha1, null_sha1, 20)) {
+               free(desc->buffer);
+               desc->alloc = desc->size = 0;
+               desc->buffer = NULL;
+               return 0; /* deletion patch */
+       }
+
+       if (has_sha1_file(sha1)) {
+               /* We already have the postimage */
+               char type[10];
+               unsigned long size;
 
-               /* For now, we do not record post-image data in the patch,
-                * and require the object already present in the recipient's
-                * object database.
+               free(desc->buffer);
+               desc->buffer = read_sha1_file(sha1, type, &size);
+               if (!desc->buffer)
+                       return error("the necessary postimage %s for "
+                                    "'%s' cannot be read",
+                                    patch->new_sha1_prefix, name);
+               desc->alloc = desc->size = size;
+       }
+       else {
+               /* We have verified desc matches the preimage;
+                * apply the patch data to it, which is stored
+                * in the patch->fragments->{patch,size}.
                 */
-               if (desc->buffer) {
-                       free(desc->buffer);
-                       desc->alloc = desc->size = 0;
-               }
-               get_sha1_hex(patch->new_sha1_prefix, sha1);
-
-               if (memcmp(sha1, null_sha1, 20)) {
-                       char type[10];
-                       unsigned long size;
-
-                       desc->buffer = read_sha1_file(sha1, type, &size);
-                       if (!desc->buffer)
-                               return error("the necessary postimage %s for "
-                                            "'%s' does not exist",
-                                            patch->new_sha1_prefix, name);
-                       desc->alloc = desc->size = size;
-               }
+               if (apply_binary_fragment(desc, patch))
+                       return error("binary patch does not apply to '%s'",
+                                    name);
 
-               return 0;
+               /* verify that the result matches */
+               write_sha1_file_prepare(desc->buffer, desc->size, blob_type,
+                                       sha1, hdr, &hdrlen);
+               if (strcmp(sha1_to_hex(sha1), patch->new_sha1_prefix))
+                       return error("binary patch to '%s' creates incorrect result", name);
        }
 
+       return 0;
+}
+
+static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
+{
+       struct fragment *frag = patch->fragments;
+       const char *name = patch->old_name ? patch->old_name : patch->new_name;
+
+       if (patch->is_binary)
+               return apply_binary(desc, patch);
+
        while (frag) {
                if (apply_one_fragment(desc, frag) < 0)
                        return error("patch failed: %s:%ld",
@@ -1651,15 +1907,14 @@ static void add_index_file(const char *path, unsigned mode, void *buf, unsigned
        if (!write_index)
                return;
 
-       ce = xmalloc(ce_size);
-       memset(ce, 0, ce_size);
+       ce = xcalloc(1, ce_size);
        memcpy(ce->name, path, namelen);
        ce->ce_mode = create_ce_mode(mode);
        ce->ce_flags = htons(namelen);
        if (lstat(path, &st) < 0)
                die("unable to stat newly created file %s", path);
        fill_stat_cache_info(ce, &st);
-       if (write_sha1_file(buf, size, "blob", ce->sha1) < 0)
+       if (write_sha1_file(buf, size, blob_type, ce->sha1) < 0)
                die("unable to create backing store for newly created file %s", path);
        if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
                die("unable to add cache entry for %s", path);
@@ -1794,7 +2049,6 @@ static int use_patch(struct patch *p)
 
 static int apply_patch(int fd, const char *filename)
 {
-       int newfd;
        unsigned long offset, size;
        char *buffer = read_patch_file(fd, &size);
        struct patch *list = NULL, **listp = &list;
@@ -1808,8 +2062,7 @@ static int apply_patch(int fd, const char *filename)
                struct patch *patch;
                int nr;
 
-               patch = xmalloc(sizeof(*patch));
-               memset(patch, 0, sizeof(*patch));
+               patch = xcalloc(1, sizeof(*patch));
                nr = parse_chunk(buffer + offset, size, patch);
                if (nr < 0)
                        break;
@@ -1826,12 +2079,11 @@ static int apply_patch(int fd, const char *filename)
                size -= nr;
        }
 
-       newfd = -1;
        if (whitespace_error && (new_whitespace == error_on_whitespace))
                apply = 0;
 
        write_index = check_index && apply;
-       if (write_index)
+       if (write_index && newfd < 0)
                newfd = hold_index_file_for_update(&cache_file, get_index_file());
        if (check_index) {
                if (read_cache() < 0)
@@ -1844,12 +2096,6 @@ static int apply_patch(int fd, const char *filename)
        if (apply)
                write_out_results(list, skipped_patch);
 
-       if (write_index) {
-               if (write_cache(newfd, active_cache, active_nr) ||
-                   commit_index_file(&cache_file))
-                       die("Unable to write new cachefile");
-       }
-
        if (show_index_info)
                show_index_list(list);
 
@@ -1884,6 +2130,7 @@ int main(int argc, char **argv)
 
        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
+               char *end;
                int fd;
 
                if (!strcmp(arg, "-")) {
@@ -1911,7 +2158,8 @@ int main(int argc, char **argv)
                        diffstat = 1;
                        continue;
                }
-               if (!strcmp(arg, "--allow-binary-replacement")) {
+               if (!strcmp(arg, "--allow-binary-replacement") ||
+                   !strcmp(arg, "--binary")) {
                        allow_binary_replacement = 1;
                        continue;
                }
@@ -1947,6 +2195,12 @@ int main(int argc, char **argv)
                        line_termination = 0;
                        continue;
                }
+               if (!strncmp(arg, "-C", 2)) {
+                       p_context = strtoul(arg + 2, &end, 0);
+                       if (*end != '\0')
+                               die("unrecognized context count '%s'", arg + 2);
+                       continue;
+               }
                if (!strncmp(arg, "--whitespace=", 13)) {
                        whitespace_option = arg + 13;
                        parse_whitespace_option(arg + 13);
@@ -2000,5 +2254,12 @@ int main(int argc, char **argv)
                                whitespace_error == 1 ? "" : "s",
                                whitespace_error == 1 ? "s" : "");
        }
+
+       if (write_index) {
+               if (write_cache(newfd, active_cache, active_nr) ||
+                   commit_index_file(&cache_file))
+                       die("Unable to write new cachefile");
+       }
+
        return 0;
 }