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| author | Elijah Newren <newren@gmail.com> | 2021-02-14 07:51:50 +0000 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2021-02-15 18:02:16 -0800 |
| commit | 07c9a7fcb50e7af9d350edc82d5f906a6eb6bd62 (patch) | |
| tree | 34fb5356a12f270f6d8d193bce43b7712983c26b /Documentation/gitdiffcore.txt | |
| parent | bd24aa2f97a08fdd5a4982bc6268f70c6bb7b747 (diff) | |
| download | git-07c9a7fcb50e7af9d350edc82d5f906a6eb6bd62.tar.gz | |
gitdiffcore doc: mention new preliminary step for rename detection
The last few patches have introduced a new preliminary step when rename
detection is on but both break detection and copy detection are off.
Document this new step. While we're at it, add a testcase that checks
the new behavior as well.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'Documentation/gitdiffcore.txt')
| -rw-r--r-- | Documentation/gitdiffcore.txt | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/gitdiffcore.txt b/Documentation/gitdiffcore.txt index c970d9fe43..80fcf95424 100644 --- a/Documentation/gitdiffcore.txt +++ b/Documentation/gitdiffcore.txt @@ -168,6 +168,26 @@ a similarity score different from the default of 50% by giving a number after the "-M" or "-C" option (e.g. "-M8" to tell it to use 8/10 = 80%). +Note that when rename detection is on but both copy and break +detection are off, rename detection adds a preliminary step that first +checks if files are moved across directories while keeping their +filename the same. If there is a file added to a directory whose +contents is sufficiently similar to a file with the same name that got +deleted from a different directory, it will mark them as renames and +exclude them from the later quadratic step (the one that pairwise +compares all unmatched files to find the "best" matches, determined by +the highest content similarity). So, for example, if a deleted +docs/ext.txt and an added docs/config/ext.txt are similar enough, they +will be marked as a rename and prevent an added docs/ext.md that may +be even more similar to the deleted docs/ext.txt from being considered +as the rename destination in the later step. For this reason, the +preliminary "match same filename" step uses a bit higher threshold to +mark a file pair as a rename and stop considering other candidates for +better matches. At most, one comparison is done per file in this +preliminary pass; so if there are several remaining ext.txt files +throughout the directory hierarchy after exact rename detection, this +preliminary step will be skipped for those files. + Note. When the "-C" option is used with `--find-copies-harder` option, 'git diff-{asterisk}' commands feed unmodified filepairs to diffcore mechanism as well as modified ones. This lets the copy |