From cfbfdb963a426c4f2f47584b83e0cc4f2f463b8b Mon Sep 17 00:00:00 2001 From: Masahiko Sawada Date: Wed, 29 Apr 2026 09:10:07 -0700 Subject: [PATCH] test_tidstore: Stabilize regression tests by sorting offsets. TidStoreSetBlockOffsets() requires its offsets array to be strictly ascending and asserts this precondition. In test_tidstore, we were passing random offset numbers deduplicated by a DISTINCT clause in an array_agg() call directly to the do_set_block_offsets() test harness. However, DISTINCT without an ORDER BY clause does not guarantee sorted results according to the SQL standard. Fix this by sorting the offsets in-place inside do_set_block_offsets() before calling TidStoreSetBlockOffsets(). While this assertion failure is not observed during regular regression tests because they use queries simple enough that the optimizer consistently chooses plans yielding sorted results, it makes sense to stabilize the test. The failure could theoretically occur depending on the optimizer's plan choice, and has been reported when experimenting with certain third-party extensions. Backpatch to v17, where test_tidstore was introduced, to ensure extension development on stable branches does not hit this assertion. Reported-by: Andrei Lepikhov Author: Andrei Lepikhov Discussion: https://postgr.es/m/b97f1850-fc7b-43c4-9b04-4e97bb9e7dc0@gmail.com Backpatch-through: 17 --- src/test/modules/test_tidstore/test_tidstore.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/src/test/modules/test_tidstore/test_tidstore.c b/src/test/modules/test_tidstore/test_tidstore.c index eb16e0fbfa6..d12d54f3677 100644 --- a/src/test/modules/test_tidstore/test_tidstore.c +++ b/src/test/modules/test_tidstore/test_tidstore.c @@ -75,6 +75,19 @@ itemptr_cmp(const void *left, const void *right) return 0; } +static int +offsetnumber_cmp(const void *a, const void *b) +{ + OffsetNumber l = *(const OffsetNumber *) a; + OffsetNumber r = *(const OffsetNumber *) b; + + if (l < r) + return -1; + else if (l > r) + return 1; + return 0; +} + /* * Create a TidStore. If shared is false, the tidstore is created * on TopMemoryContext, otherwise on DSA. Although the tidstore @@ -179,6 +192,9 @@ do_set_block_offsets(PG_FUNCTION_ARGS) noffs = ArrayGetNItems(ARR_NDIM(ta), ARR_DIMS(ta)); offs = ((OffsetNumber *) ARR_DATA_PTR(ta)); + /* TidStoreSetBlockOffsets() requires offsets to be strictly ascending. */ + qsort(offs, noffs, sizeof(OffsetNumber), offsetnumber_cmp); + /* Set TIDs in the store */ TidStoreLockExclusive(tidstore); TidStoreSetBlockOffsets(tidstore, blkno, offs, noffs);