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author | Elijah Newren <newren@gmail.com> | 2018-08-29 00:06:13 -0700 |
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committer | Junio C Hamano <gitster@pobox.com> | 2018-08-30 07:58:59 -0700 |
commit | 6aba117d5cf7128e7bc942888263552fe927e13f (patch) | |
tree | 2cbc8868390321a969fa938a961bc618a9124d98 /t/t4013/diff.log_--root_master | |
parent | merge-recursive: add ability to turn off directory rename detection (diff) | |
download | tgif-6aba117d5cf7128e7bc942888263552fe927e13f.tar.xz |
am: avoid directory rename detection when calling recursive merge machinery
Let's say you have the following three trees, where Base is from one commit
behind either master or branch:
Base : bar_v1, foo/{file1, file2, file3}
branch: bar_v2, foo/{file1, file2}, goo/file3
master: bar_v3, foo/{file1, file2, file3}
Using git-am (or am-based rebase) to apply the changes from branch onto
master results in the following tree:
Result: bar_merged, goo/{file1, file2, file3}
This is not what users want; they did not rename foo/ -> goo/, they only
renamed one file within that directory. The reason this happens is am
constructs fake trees (via build_fake_ancestor()) of the following form:
Base_bfa : bar_v1, foo/file3
branch_bfa: bar_v2, goo/file3
Combining these two trees with master's tree:
master: bar_v3, foo/{file1, file2, file3},
You can see that merge_recursive_generic() would see branch_bfa as renaming
foo/ -> goo/, and master as just adding both foo/file1 and foo/file2. As
such, it ends up with goo/{file1, file2, file3}
The core problem is that am does not have access to the original trees; it
can only construct trees using the blobs involved in the patch. As such,
it is not safe to perform directory rename detection within am -3.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 't/t4013/diff.log_--root_master')
0 files changed, 0 insertions, 0 deletions