The checks added in 3444ec2 to ensure that the fsmonitor_dirty bitmap does not have more bits than the index do not play well with the split index. git update-index --fsmonitor --split-index calls write_locked_index which calls write_shared_index as well as write_split_index. The first call fills up the fsmonitor_dirty bitmap, and the second modifies the index such that istate->cache_nr is zero and this assert is hit. The test written does reproduce the error, but only flakily. There is limited difference with GIT_TEST_FSMONITOR=fsmonitor-all or GIT_TEST_FSMONITOR=fsmonitor-watchman, so the flakiness might come from somewhere else, which I haven't tracked down. The test also requires checkout of a new branch, and checking out back to master. It's clear that the index gets into some poor state through these operations, and there is a deeper bug somewhere. At the very least, this patch mitigates an over-eager check for split index users while maintaining good invariants for the standard case. Also, I haven't been able to reproduce this with "standard" user commands, like status/checkout/stash, so the blast radius seems limited. Helped-by: Kevin Willford kewillf@xxxxxxxxxxxxx [kewillf@xxxxxxxxxxxxx] Helped-by: Junio C Hamano gitster@xxxxxxxxx [gitster@xxxxxxxxx] Signed-off-by: Utsav Shah utsav@xxxxxxxxxxx [utsav@xxxxxxxxxxx] Utsav Shah (1): fsmonitor: skip sanity check if the index is split fsmonitor.c | 8 ++++---- t/t7519-status-fsmonitor.sh | 23 +++++++++++++++++++++++ 2 files changed, 27 insertions(+), 4 deletions(-) base-commit: 566a1439f6f56c2171b8853ddbca0ad3f5098770 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-458%2FUtsav2%2Fsplit-fix-v1 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-458/Utsav2/split-fix-v1 Pull-Request: https://github.com/gitgitgadget/git/pull/458 -- gitgitgadget
