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| author | Nguyễn Thái Ngọc Duy <pclouds@gmail.com> | 2018-01-24 16:38:29 +0700 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2018-01-24 10:09:18 -0800 |
| commit | ef5b3a6c5e24c54ba4436e225b9431c63ab163f0 (patch) | |
| tree | af11b8f8180dff20a3cee936c7935e455ab3d963 | |
| parent | 59f9d2dd60f97c55c92c3273903f64048a27e513 (diff) | |
| download | git-nd/shared-index-fix.tar.gz | |
read-cache: don't write index twice if we can't write shared indexnd/shared-index-fix
In a0a967568e ("update-index --split-index: do not split if $GIT_DIR is
read only", 2014-06-13), we tried to make sure we can still write an
index, even if the shared index can not be written.
We did so by just calling 'do_write_locked_index()' just before
'write_shared_index()'. 'do_write_locked_index()' always at least
closes the tempfile nowadays, and used to close or commit the lockfile
if COMMIT_LOCK or CLOSE_LOCK were given at the time this feature was
introduced. COMMIT_LOCK or CLOSE_LOCK is passed in by most callers of
'write_locked_index()'.
After calling 'write_shared_index()', we call 'write_split_index()',
which calls 'do_write_locked_index()' again, which then tries to use the
closed lockfile again, but in fact fails to do so as it's already
closed. This eventually leads to a segfault.
Make sure to write the main index only once.
[nd: most of the commit message and investigation done by Thomas, I only
tweaked the solution a bit]
Helped-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
| -rw-r--r-- | read-cache.c | 5 | ||||
| -rwxr-xr-x | t/t1700-split-index.sh | 19 |
2 files changed, 22 insertions, 2 deletions
diff --git a/read-cache.c b/read-cache.c index c568643f55..c58c0a978a 100644 --- a/read-cache.c +++ b/read-cache.c @@ -2561,8 +2561,9 @@ int write_locked_index(struct index_state *istate, struct lock_file *lock, if (!temp) { hashclr(si->base_sha1); ret = do_write_locked_index(istate, lock, flags); - } else - ret = write_shared_index(istate, &temp); + goto out; + } + ret = write_shared_index(istate, &temp); saved_errno = errno; if (is_tempfile_active(temp)) diff --git a/t/t1700-split-index.sh b/t/t1700-split-index.sh index af9b847761..cbcefa6e5f 100755 --- a/t/t1700-split-index.sh +++ b/t/t1700-split-index.sh @@ -401,4 +401,23 @@ done <<\EOF 0642 -rw-r---w- EOF +test_expect_success POSIXPERM,SANITY 'graceful handling when splitting index is not allowed' ' + test_create_repo ro && + ( + cd ro && + test_commit initial && + git update-index --split-index && + test -f .git/sharedindex.* + ) && + cp ro/.git/index new-index && + test_when_finished "chmod u+w ro/.git" && + chmod u-w ro/.git && + GIT_INDEX_FILE="$(pwd)/new-index" git -C ro update-index --split-index && + chmod u+w ro/.git && + rm ro/.git/sharedindex.* && + GIT_INDEX_FILE=new-index git ls-files >actual && + echo initial.t >expected && + test_cmp expected actual +' + test_done |