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 <junkio@cox.net>
This commit is contained in:
Junio C Hamano 2005-11-14 17:37:05 -08:00
parent 0c15cc921a
commit 011f4274bb
3 changed files with 101 additions and 7 deletions

View File

@ -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] [<patch>...]
'git-apply' [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] [<patch>...]
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 <torvalds@osdl.org>

87
apply.c
View File

@ -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] <patch>...";
"git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] <patch>...";
/*
* 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;

View File

@ -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.' \