Am 16.07.2017 um 02:28 schrieb Ramsay Jones:
On 15/07/17 21:11, René Scharfe wrote:Exit early when asked to prune an index that contains no entries to begin with. This avoids pointer arithmetic on istate->cache, which is possibly NULL in that case. Found with Clang's UBSan. Signed-off-by: Rene Scharfe <l.s.r@xxxxxx> --- builtin/ls-files.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/builtin/ls-files.c b/builtin/ls-files.c index b8514a0029..adf572da68 100644 --- a/builtin/ls-files.c +++ b/builtin/ls-files.c @@ -362,7 +362,7 @@ static void prune_index(struct index_state *istate, int pos; unsigned int first, last; - if (!prefix) + if (!prefix || !istate->cache_nr) return; pos = index_name_pos(istate, prefix, prefixlen); if (pos < 0)My patch looked like: - if (!prefix) + if (!prefix || !istate->cache || istate->cache_nr == 0) ... which is probably a bit 'belt-n-braces'. ;-)
Not checking for !istate->cache at this point is a good thing, I think. If we have entries, then ->cache must not be NULL, and if it is we'd get a segfault, notifying us that we have a bug. We could add an assert to state this requirement explicitly, but that would be the topic of a different patch. René
