diff options
Diffstat (limited to 'apply.c')
| -rw-r--r-- | apply.c | 232 |
1 files changed, 172 insertions, 60 deletions
@@ -10,6 +10,7 @@ #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 @@ -966,6 +967,70 @@ 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) +{ + /* We have read "GIT binary patch\n"; what follows is a + * sequence of 'length-byte' followed by base-85 encoded + * delta data. + * + * 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 *delta = NULL; + + patch->is_binary = 1; + patch->fragments = fragment = xcalloc(1, sizeof(*fragment)); + used = 0; + 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; + delta = xrealloc(delta, newsize); + if (decode_85(delta + fragment->size, + buffer + 1, + byte_length)) + goto corrupt; + fragment->size = newsize; + buffer += llen; + size -= llen; + } + fragment->patch = delta; + 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; @@ -982,19 +1047,34 @@ 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 @@ -1345,76 +1425,108 @@ 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 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_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); - } + 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); + } + + 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)) + return 0; /* deletion patch */ + + if (has_sha1_file(sha1)) { + 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. + 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 { + char type[10]; + unsigned long src_size, dst_size; + void *src; + + get_sha1_hex(patch->old_sha1_prefix, sha1); + src = read_sha1_file(sha1, type, &src_size); + if (!src) + return error("the necessary preimage %s for " + "'%s' cannot be read", + patch->old_sha1_prefix, name); + + /* patch->fragment->patch has the delta data and + * we should apply it to the preimage. */ - 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; - } + desc->buffer = patch_delta(src, src_size, + (void*) patch->fragments->patch, + patch->fragments->size, + &dst_size); + if (!desc->buffer) + return error("binary patch does not apply to '%s'", + name); + desc->size = desc->alloc = dst_size; - 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", |