merge: fix incorrect rename detection for empty files. #6717
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ethomson
reviewed
Jan 15, 2024
When merging trees containing multiple empty files, make sure a rename is not detected between each empty files. For example Ancestor has files: * foo.c with content * bar.c empty Ours has: * foo.c with content * boo.c empty Theirs has: * foo.c with other content * bar.c with content merge_trees() will incorrectly apply the content of theirs's 'bar.c' in ours's boo.c' thinking 'bar.c' has been renamed to 'boo.c'. This happens because both are empty and their sha1 are the same. Thus merge_diff_mark_similarity_exact() incorrectly mark it as renamed. Signed-off-by: Gregory Herrero <gregory.herrero@oracle.com>
Add a boolean option to merge_trivial() so that it can use theirs parent instead of merge base as ancestor. This will be needed in the following commit. Signed-off-by: Gregory Herrero <gregory.herrero@oracle.com>
This test follow "merge: fix incorrect rename detection for empty files." commit. Signed-off-by: Gregory Herrero <gregory.herrero@oracle.com>
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Don't munge the "trivial" tests, those are specifically about the "trivial" resolutions for git's tree merge. (For example, adding a file in a new branch and making no changes in the HEAD branch is something that can be handled _trivially_.) For tests of rename functionality, put them in the trees::rename tests.
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👋 Thanks for the fix - sorry it's taken so long to come back to it. I did make one change, which was just to move the test out of the |
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When merging trees containing multiple empty files, make sure a rename
is not detected between each empty files.
For example
Ancestor has files:
Ours has:
Theirs has:
merge_trees()will incorrectly apply the content of theirs'sbar.cinours's
boo.cthinkingbar.chas been renamed toboo.c.This happens because both are empty and their sha1 are the same. Thus
merge_diff_mark_similarity_exact()incorrectly mark it as renamed.