Subject: [PATCH] apply: fix copy/rename breakage

From: Junio C Hamano <[email-masked]>
Date: Wed, 09 Jul 2008 20:10:58 -0700

Recently, 7ebd52a (Merge branch 'dz/apply-again', 2008-07-01) taught
"git-apply" to grok a (non-git) patch that is a concatenation of separate
patches that touch the same file number of files, by recording the
postimage of patch application of previous round and using it as the
preimage for later rounds.

However, this "incremental" mode of patch application contradicts with the
way git rename/copy patches are fundamentally designed.  When a git patch
talks about a file A getting modified, and a new file B created out of B,
like this:

	diff --git a/A b/A
	--- a/A
	+++ b/A
	... change text here ...
	diff --git a/A b/B
	copy from A
	copy to B
	--- a/A
	+++ b/B
	... change text here ...

the second change to produce B does not depend on what is done to A with
the first change (this is explicitly done so for reviewability of
individual patches).

With this patch, we disable the postimage record 'fn_table' when applying
a patch to produce new files out of existing file by copying to fix this
issue.

Signed-off-by: Junio C Hamano <[email-masked]>
---

 * Applies to 'master'.  I am CC'ing Linus not because he is in any way
   responsible for this breakage, but because this breakage can affect
   heavy users of "git apply".

 builtin-apply.c |   10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/builtin-apply.c b/builtin-apply.c
index b3fc290..d13313f 100644
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@ -2296,7 +2296,8 @@ static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *
 
 	strbuf_init(&buf, 0);
 
-	if ((tpatch = in_fn_table(patch->old_name)) != NULL) {
+	if (!(patch->is_copy || patch->is_rename) &&
+	    ((tpatch = in_fn_table(patch->old_name)) != NULL)) {
 		if (tpatch == (struct patch *) -1) {
 			return error("patch %s has been renamed/deleted",
 				patch->old_name);
@@ -2375,7 +2376,7 @@ static int verify_index_match(struct cache_entry *ce, struct stat *st)
 static int check_preimage(struct patch *patch, struct cache_entry **ce, struct stat *st)
 {
 	const char *old_name = patch->old_name;
-	struct patch *tpatch;
+	struct patch *tpatch = NULL;
 	int stat_ret = 0;
 	unsigned st_mode = 0;
 
@@ -2389,7 +2390,9 @@ static int check_preimage(struct patch *patch, struct cache_entry **ce, struct s
 		return 0;
 
 	assert(patch->is_new <= 0);
-	if ((tpatch = in_fn_table(old_name)) != NULL) {
+
+	if (!(patch->is_copy || patch->is_rename) &&
+	    (tpatch = in_fn_table(old_name)) != NULL) {
 		if (tpatch == (struct patch *) -1) {
 			return error("%s: has been deleted/renamed", old_name);
 		}
@@ -2399,6 +2402,7 @@ static int check_preimage(struct patch *patch, struct cache_entry **ce, struct s
 		if (stat_ret && errno != ENOENT)
 			return error("%s: %s", old_name, strerror(errno));
 	}
+
 	if (check_index && !tpatch) {
 		int pos = cache_name_pos(old_name, strlen(old_name));
 		if (pos < 0) {
-- 
1.5.6.2.291.g7eef3