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authorJeff King <peff@peff.net>2012-03-22 18:52:24 -0400
committerJunio C Hamano <gitster@pobox.com>2012-03-23 13:52:51 -0700
commit4f7cb99ada26be5d86402a6e060f3ee16a672f16 (patch)
treeb12a4eed448bc55dca8463f5abe52eae37c8be94
parent90d43b07687fdc51d1f2fc14948df538dc45584b (diff)
downloadgit-jk/diff-no-rename-empty.tar.gz
merge-recursive: don't detect renames of empty filesjk/diff-no-rename-empty
Merge-recursive detects renames so that if one side modifies "foo" and the other side moves it to "bar", the modification is applied to "bar". However, our rename detection is based on content analysis, it can be wrong (i.e., two files were not intended as a rename, but just happen to have the same or similar content). This is quite rare if the files actually contain content, since two unrelated files are unlikely to have exactly the same content. However, empty files present a problem, in that there is nothing to analyze. An uninteresting placeholder file with zero bytes may or may not be related to a placeholder file with another name. The result is that adding content to an empty file may cause confusion if the other side of a merge removed it; your content may end up in another random placeholder file that was added. Let's err on the side of caution and not consider empty files as renames. This will cause a modify/delete conflict on the merge, which will let the user sort it out themselves. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
-rw-r--r--merge-recursive.c1
-rwxr-xr-xt/t6022-merge-rename.sh16
2 files changed, 17 insertions, 0 deletions
diff --git a/merge-recursive.c b/merge-recursive.c
index 318d32e223..0fb174359a 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -485,6 +485,7 @@ static struct string_list *get_renames(struct merge_options *o,
renames = xcalloc(1, sizeof(struct string_list));
diff_setup(&opts);
DIFF_OPT_SET(&opts, RECURSIVE);
+ DIFF_OPT_CLR(&opts, RENAME_EMPTY);
opts.detect_rename = DIFF_DETECT_RENAME;
opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
o->diff_rename_limit >= 0 ? o->diff_rename_limit :
diff --git a/t/t6022-merge-rename.sh b/t/t6022-merge-rename.sh
index 9d8584e957..1104249182 100755
--- a/t/t6022-merge-rename.sh
+++ b/t/t6022-merge-rename.sh
@@ -884,4 +884,20 @@ test_expect_success 'no spurious "refusing to lose untracked" message' '
! grep "refusing to lose untracked file" errors.txt
'
+test_expect_success 'do not follow renames for empty files' '
+ git checkout -f -b empty-base &&
+ >empty1 &&
+ git add empty1 &&
+ git commit -m base &&
+ echo content >empty1 &&
+ git add empty1 &&
+ git commit -m fill &&
+ git checkout -b empty-topic HEAD^ &&
+ git mv empty1 empty2 &&
+ git commit -m rename &&
+ test_must_fail git merge empty-base &&
+ >expect &&
+ test_cmp expect empty2
+'
+
test_done