On 8/16/2021 1:48 PM, Derrick Stolee via GitGitGadget wrote: > From: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx> > > Copy the 'index_state->dir_hash' back to the real istate after expanding > a sparse index. > > A crash was observed in 'git status' during some hashmap lookups with > corrupted hashmap entries. During an index expansion, new cache-entries > are added to the 'index_state->name_hash' and the 'dir_hash' in a > temporary 'index_state' variable 'full'. However, only the 'name_hash' > hashmap from this temp variable was copied back into the real 'istate' > variable. The original copy of the 'dir_hash' was incorrectly > preserved. If the table in the 'full->dir_hash' hashmap were realloced, > the stale version (in 'istate') would be corrupted. > > The test suite does not operate on index sizes sufficiently large to > trigger this reallocation, so they do not cover this behavior. > Increasing the test suite to cover such scale is fragile and likely > wasteful. > > Signed-off-by: Jeff Hostetler <jeffhost@xxxxxxxxxxxxx> > Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx> > --- > sparse-index: copy dir_hash in ensure_full_index() > > This fix is an issue we discovered in our first experimental release of > the sparse index in the microsoft/git fork. We fixed it in the latest > experimental release [1] and then I almost forgot about it until we > started rebasing sparse-index work on top of the 2.33.0 release > candidates. > > [1] https://github.com/microsoft/git/releases/tag/v2.32.0.vfs.0.102.exp > > This is a change that can be taken anywhere since 4300f8 (sparse-index: > implement ensure_full_index(), 2021-03-30), but this version is based on > v2.33.0-rc2. I sent this patch on the day of v2.33.0, so I'm not surprised that it got lost in the shuffle. Could someone please take a look? It also has not been picked up for the What's Cooking email. Thanks, -Stolee
