[PATCH 2/2] merge-recursive: don't detect renames of empty files
- From
Jeff King <peff@peff.net>
- Date
- Mar 22, 2012, 22:52 UTC
- Message-ID
- <20120322225223.GB14902@sigill.intra.peff.net>
- In-Reply-To
- <20120322224651.GA14874@sigill.intra.peff.net>
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> --- merge-recursive.c | 1 + t/t6022-merge-rename.sh | 16 ++++++++++++++++ 2 files changed, 17 insertions(+)
diff --git a/merge-recursive.c b/merge-recursive.c index 318d32e..0fb1743 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 9d8584e..1104249 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
-- 1.7.10.rc0.9.gdcbe9