From 4c490f3d321da415b8d3bec4a04565906657b9c9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?SZEDER=20G=C3=A1bor?= Date: Thu, 11 Oct 2018 11:53:57 +0200 Subject: [PATCH] split-index: BUG() when cache entry refers to non-existing shared entry MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When the split index feature is in use, then a cache entry is: - either only present in the split index, in which case its 'index' field must be 0, - or it should refer to an existing entry in the shared index, i.e. the 'index' field can't be greater than the size of the shared index. If a cache entry were to refer to a non-existing entry in the shared index, then that's a sign of something being wrong in the index state, either as a result of a bug in dealing with the split/shared index entries, or perhaps a (potentially unrelated) memory corruption issue. prepare_to_write_split_index() already has a condition to catch cache entries with such bogus 'index' field, but instead of calling BUG() it just sets cache entry's 'index = 0', and the entry will then be written to the new split index. Don't write a new index file from bogus index state, and call BUG() upon encountering an cache entry referring to a non-existing shared index entry. Running the test suite repeatedly with 'GIT_TEST_SPLIT_INDEX=yes' doesn't trigger this condition. Signed-off-by: SZEDER Gábor Signed-off-by: Junio C Hamano --- split-index.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/split-index.c b/split-index.c index 875f538802..5820412dc5 100644 --- a/split-index.c +++ b/split-index.c @@ -254,8 +254,8 @@ void prepare_to_write_split_index(struct index_state *istate) continue; } if (ce->index > si->base->cache_nr) { - ce->index = 0; - continue; + BUG("ce refers to a shared ce at %d, which is beyond the shared index size %d", + ce->index, si->base->cache_nr); } ce->ce_flags |= CE_MATCHED; /* or "shared" */ base = si->base->cache[ce->index - 1];