From 011f4274bbb14e44035586f2ede695d584b8cfd2 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Mon, 14 Nov 2005 17:37:05 -0800 Subject: apply: allow-binary-replacement. A new option, --allow-binary-replacement, is introduced. When you feed a diff that records full SHA1 name of pre- and post-image blob on its index line to git-apply with this option, the post-image blob replaces the path if what you have in the working tree matches the pre-image _and_ post-image blob is already available in the object directory. Later we _might_ want to enhance the diff output to also include the full binary data of the post-image, to make this more useful, but this is good enough for local rebasing application. Signed-off-by: Junio C Hamano diff --git a/Documentation/git-apply.txt b/Documentation/git-apply.txt index 6702a18..626e281 100644 --- a/Documentation/git-apply.txt +++ b/Documentation/git-apply.txt @@ -8,7 +8,7 @@ git-apply - Apply patch on a git index file and a work tree SYNOPSIS -------- -'git-apply' [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [-z] [...] +'git-apply' [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] [...] DESCRIPTION ----------- @@ -79,6 +79,17 @@ OPTIONS the result with this option, which would apply the deletion part but not addition part. +--allow-binary-replacement:: + When applying a patch, which is a git-enhanced patch + that was prepared to record the pre- and post-image object + name in full, and the path being patched exactly matches + the object the patch applies to (i.e. "index" line's + pre-image object name is what is in the working tree), + and the post-image object is available in the object + database, use the post-image object as the patch + result. This allows binary files to be patched in a + very limited way. + Author ------ Written by Linus Torvalds diff --git a/apply.c b/apply.c index a002e15..129edb1 100644 --- a/apply.c +++ b/apply.c @@ -16,6 +16,7 @@ // --numstat does numeric diffstat, and doesn't actually apply // --index-info shows the old and new index info for paths if available. // +static int allow_binary_replacement = 0; static int check_index = 0; static int write_index = 0; static int diffstat = 0; @@ -27,7 +28,7 @@ static int no_add = 0; static int show_index_info = 0; static int line_termination = '\n'; static const char apply_usage[] = -"git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [-z] ..."; +"git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] ..."; /* * For "diff-stat" like behaviour, we keep track of the biggest change @@ -900,11 +901,13 @@ static int parse_chunk(char *buffer, unsigned long size, struct patch *patch) patch->is_binary = 1; /* Empty patch cannot be applied if: - * - it is a binary patch or - * - metadata does not change and is not a binary patch. + * - it is a binary patch and we do not do binary_replace, or + * - text patch without metadata change */ if ((apply || check) && - (patch->is_binary || !metadata_changes(patch))) + (patch->is_binary + ? !allow_binary_replacement + : !metadata_changes(patch))) die("patch with only garbage at line %d", linenr); } @@ -1158,10 +1161,77 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag) 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) { + unsigned char sha1[20]; + + 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); + + 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); + } + + /* For now, we do not record post-image data in the patch, + * and require the object already present in the recipient's + * object database. + */ + 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; + } + + return 0; + } while (frag) { if (apply_one_fragment(desc, frag) < 0) - return error("patch failed: %s:%ld", patch->old_name, frag->oldpos); + return error("patch failed: %s:%ld", + name, frag->oldpos); frag = frag->next; } return 0; @@ -1203,6 +1273,7 @@ static int check_patch(struct patch *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; if (old_name) { int changed; @@ -1277,7 +1348,7 @@ static int check_patch(struct patch *patch) } if (apply_data(patch, &st) < 0) - return error("%s: patch does not apply", old_name); + return error("%s: patch does not apply", name); return 0; } @@ -1726,6 +1797,10 @@ int main(int argc, char **argv) diffstat = 1; continue; } + if (!strcmp(arg, "--allow-binary-replacement")) { + allow_binary_replacement = 1; + continue; + } if (!strcmp(arg, "--numstat")) { apply = 0; numstat = 1; diff --git a/t/t4103-apply-binary.sh b/t/t4103-apply-binary.sh index 948d5b5..9057f6d 100644 --- a/t/t4103-apply-binary.sh +++ b/t/t4103-apply-binary.sh @@ -51,6 +51,14 @@ test_expect_failure 'check binary diff (copy) -- should fail.' \ 'git-checkout master git-apply --check C.diff' +test_expect_failure 'check incomplete binary diff with replacement -- should fail.' \ + 'git-checkout master + git-apply --check --allow-binary-replacement B.diff' + +test_expect_failure 'check incomplete binary diff with replacement (copy) -- should fail.' \ + 'git-checkout master + git-apply --check --allow-binary-replacement C.diff' + # Now we start applying them. test_expect_failure 'apply binary diff -- should fail.' \ -- cgit v0.10.2-6-g49f6