On Wed, Jul 16, 2025 at 06:19:32PM -0700, Kyle Lippincott wrote: > Unfortunately I can't provide great instructions for reproducing this > locally, because it relies on our internal build stack (which uses > blaze). Getting MemorySanitizer running can be quite annoying, though > you might not have any issues if this test doesn't invoke any third > party libraries (like zlib). > > I need to sign off for the night soon, but if this isn't sufficient > enough information to identify what's happening here, I can try to dig > deeper tomorrow. This run was executed on an import of upstream commit > 4ea3c74afd42a503b3e0d60e1fec33bc0431e7bc (Junio's merge of this > series) valgrind can often find the same issues as MSan without as much headache to get it running (the downside is that it is _way_ slower). And indeed: git checkout 4ea3c74afd42a503b3e0d60e1fec33bc0431e7bc && make && (cd t && ./t6302-for-each-ref-filter.sh --valgrind-only=48) yields: ==2177572== Conditional jump or move depends on uninitialised value(s) ==2177572== at 0x3BC380: cache_ref_iterator_advance (ref-cache.c:409) ==2177572== by 0x3B69D7: ref_iterator_advance (iterator.c:15) ==2177572== by 0x3B6CC3: merge_ref_iterator_advance (iterator.c:179) ==2177572== by 0x3B69D7: ref_iterator_advance (iterator.c:15) ==2177572== by 0x3A9770: files_ref_iterator_advance (files-backend.c:902) ==2177572== by 0x3B69D7: ref_iterator_advance (iterator.c:15) ==2177572== by 0x3B7457: do_for_each_ref_iterator (iterator.c:478) ==2177572== by 0x399B43: for_each_fullref_with_seek (ref-filter.c:2718) ==2177572== by 0x399C09: for_each_fullref_in_pattern (ref-filter.c:2756) ==2177572== by 0x39B031: do_filter_refs (ref-filter.c:3263) ==2177572== by 0x39B2B7: filter_and_format_refs (ref-filter.c:3364) ==2177572== by 0x18C1D2: cmd_for_each_ref (for-each-ref.c:115) ==2177572== Uninitialised value was created by a heap allocation ==2177572== at 0x484BDD0: realloc (vg_replace_malloc.c:1801) ==2177572== by 0x44E941: xrealloc (wrapper.c:140) ==2177572== by 0x3BCAD9: cache_ref_iterator_begin (ref-cache.c:580) ==2177572== by 0x3A988A: files_ref_iterator_begin (files-backend.c:995) ==2177572== by 0x3A295E: refs_ref_iterator_begin (refs.c:1776) ==2177572== by 0x399AF6: for_each_fullref_with_seek (ref-filter.c:2710) ==2177572== by 0x399C09: for_each_fullref_in_pattern (ref-filter.c:2756) ==2177572== by 0x39B031: do_filter_refs (ref-filter.c:3263) ==2177572== by 0x39B2B7: filter_and_format_refs (ref-filter.c:3364) ==2177572== by 0x18C1D2: cmd_for_each_ref (for-each-ref.c:115) ==2177572== by 0x128C90: run_builtin (git.c:480) ==2177572== by 0x1290EB: handle_builtin (git.c:746) Bisecting doesn't tell us much, though (the first commit that introduces the test shows the problem). I didn't dig further than that. -Peff
