nocfbot_chao_test.diff

diff --git a/src/backend/nodes/bitmapset.c b/src/backend/nodes/bitmapset.c
index 48514a3b781..50201780204 100644
--- a/src/backend/nodes/bitmapset.c
+++ b/src/backend/nodes/bitmapset.c
@@ -1010,6 +1010,7 @@ bms_offset_members(Bitmapset *a, int offset)
 	int			new_nwords;
 	int			old_nwords;
 	int32		high_bit;
+	int64		old_highest;
 
 	Assert(bms_is_valid_set(a));
 
@@ -1022,6 +1023,7 @@ bms_offset_members(Bitmapset *a, int offset)
 	offset_bits = BITNUM(offset);
 	new_nwords = a->nwords + offset_words;
 	high_bit = bmw_leftmost_one_pos(a->words[a->nwords - 1]);
+	old_highest = ((int64) a->nwords - 1) * BITS_PER_BITMAPWORD + high_bit;
 
 	/* Adjust the number of words in the new set to how many we'll need */
 	new_nwords += (offset_bits + high_bit) >= BITS_PER_BITMAPWORD;
@@ -1041,7 +1043,8 @@ bms_offset_members(Bitmapset *a, int offset)
 		 * An unlikely scenario, but check we're not going to create a member
 		 * greater than PG_INT32_MAX.
 		 */
-		if (((uint64) new_nwords - 1) * BITS_PER_BITMAPWORD + high_bit + offset_bits > PG_INT32_MAX)
+		/*if (((uint64) new_nwords - 1) * BITS_PER_BITMAPWORD + high_bit + offset_bits > PG_INT32_MAX)*/
+		if (old_highest + offset > PG_INT32_MAX)
 			elog(ERROR, "bitmapset overflow");
 
 		/*
diff --git a/src/test/modules/test_bitmapset/expected/test_bitmapset.out b/src/test/modules/test_bitmapset/expected/test_bitmapset.out
index 3a6f08427cd..984174cfaf7 100644
--- a/src/test/modules/test_bitmapset/expected/test_bitmapset.out
+++ b/src/test/modules/test_bitmapset/expected/test_bitmapset.out
@@ -1613,4 +1613,14 @@ SELECT test_random_offset_operations(-1, 10000, 1024, 0) AS result;
   10000
 (1 row)
 
+-- 2147483583 is PG_INT32_MAX - 64, so offsetting by 1 should succeed,
+-- but offsetting it by 65 should fail with overflow error
+SELECT test_random_offset_operations_check_highest(2147483583, 1) AS result;
+   result   
+------------
+ 2147483584
+(1 row)
+
+SELECT test_random_offset_operations_check_highest(2147483583, 65) AS result;
+ERROR:  bitmapset overflow
 DROP EXTENSION test_bitmapset;
diff --git a/src/test/modules/test_bitmapset/sql/test_bitmapset.sql b/src/test/modules/test_bitmapset/sql/test_bitmapset.sql
index 5c5cfe3fc15..072d264ad9a 100644
--- a/src/test/modules/test_bitmapset/sql/test_bitmapset.sql
+++ b/src/test/modules/test_bitmapset/sql/test_bitmapset.sql
@@ -416,4 +416,9 @@ SELECT test_random_operations(-1, 10000, 81920, 0) > 0 AS result;
 -- perform some random test on bms_offset_members()
 SELECT test_random_offset_operations(-1, 10000, 1024, 0) AS result;
 
+-- 2147483583 is PG_INT32_MAX - 64, so offsetting by 1 should succeed,
+-- but offsetting it by 65 should fail with overflow error
+SELECT test_random_offset_operations_check_highest(2147483583, 1) AS result;
+SELECT test_random_offset_operations_check_highest(2147483583, 65) AS result;
+
 DROP EXTENSION test_bitmapset;
diff --git a/src/test/modules/test_bitmapset/test_bitmapset--1.0.sql b/src/test/modules/test_bitmapset/test_bitmapset--1.0.sql
index ea12ec40057..88bf6719aa6 100644
--- a/src/test/modules/test_bitmapset/test_bitmapset--1.0.sql
+++ b/src/test/modules/test_bitmapset/test_bitmapset--1.0.sql
@@ -145,4 +145,8 @@ CREATE FUNCTION test_random_offset_operations(integer, integer, integer, integer
 RETURNS integer STRICT
 AS 'MODULE_PATHNAME' LANGUAGE C;
 
+CREATE FUNCTION test_random_offset_operations_check_highest(integer, integer)
+RETURNS integer STRICT
+AS 'MODULE_PATHNAME' LANGUAGE C;
+
 COMMENT ON EXTENSION test_bitmapset IS 'Test code for Bitmapset';
diff --git a/src/test/modules/test_bitmapset/test_bitmapset.c b/src/test/modules/test_bitmapset/test_bitmapset.c
index 1fbf9ffc200..59da3fb78ca 100644
--- a/src/test/modules/test_bitmapset/test_bitmapset.c
+++ b/src/test/modules/test_bitmapset/test_bitmapset.c
@@ -67,6 +67,7 @@ PG_FUNCTION_INFO_V1(test_bitmap_match);
 /* Test utility functions */
 PG_FUNCTION_INFO_V1(test_random_operations);
 PG_FUNCTION_INFO_V1(test_random_offset_operations);
+PG_FUNCTION_INFO_V1(test_random_offset_operations_check_highest);
 
 /* Convenient macros to test results */
 #define EXPECT_TRUE(expr)	\
@@ -827,3 +828,20 @@ test_random_offset_operations(PG_FUNCTION_ARGS)
 
 	PG_RETURN_INT32(num_ops);
 }
+
+Datum
+test_random_offset_operations_check_highest(PG_FUNCTION_ARGS)
+{
+	int highest_member = 0;
+	int offset = 0;
+	Bitmapset  *bms;
+
+	highest_member = PG_GETARG_INT32(0);
+	offset = PG_GETARG_INT32(1);
+
+	bms = bms_add_member(NULL, highest_member);
+	bms = bms_offset_members(bms, offset);
+	highest_member = bms_next_member(bms, -1);
+
+	PG_RETURN_INT32(highest_member);
+}
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