Merge pull request #171264 from virajchogle/width-bucket-equal-bounds-171263

sql: reject equal bounds in width_bucket

Author: rail

pkg/sql/logictest/testdata/logic_test/builtin_function

@@ -2999,6 +2999,28 @@ SELECT width_bucket('Infinity'::numeric, 1, 10, 0)
 statement error pgcode 2201G pq: count must be greater than zero
 SELECT width_bucket('-Infinity'::numeric, 1, 10, -1)
 
+# Match PostgreSQL's "lower bound cannot equal upper bound" rejection
+# for both overloads, across operand positions (above, below, at the
+# degenerate point). Without the guard, the helper divides by zero
+# and casts +/-Inf or NaN to int, producing INT64_MAX, INT64_MIN, or 0.
+statement error pgcode 2201G pq: lower bound cannot equal upper bound
+SELECT width_bucket(7::numeric, 5::numeric, 5::numeric, 10::int)
+
+statement error pgcode 2201G pq: lower bound cannot equal upper bound
+SELECT width_bucket(3::numeric, 5::numeric, 5::numeric, 10::int)
+
+statement error pgcode 2201G pq: lower bound cannot equal upper bound
+SELECT width_bucket(5::numeric, 5::numeric, 5::numeric, 10::int)
+
+statement error pgcode 2201G pq: lower bound cannot equal upper bound
+SELECT width_bucket(7, 5, 5, 10)
+
+statement error pgcode 2201G pq: lower bound cannot equal upper bound
+SELECT width_bucket(3, 5, 5, 10)
+
+statement error pgcode 2201G pq: lower bound cannot equal upper bound
+SELECT width_bucket(5, 5, 5, 10)
+
 
 # Sanity check pg_type_is_visible.
 query BBB

pkg/sql/sem/builtins/math_builtins.go

@@ -739,6 +739,12 @@ var mathBuiltins = map[string]builtinDefinition{
 						"count must be greater than zero",
 					)
 				}
+				if b1 == b2 {
+					return nil, pgerror.New(
+						pgcode.InvalidArgumentForWidthBucketFunction,
+						"lower bound cannot equal upper bound",
+					)
+				}
 				if math.IsInf(operand, 1) {
 					return tree.NewDInt(tree.DInt(count + 1)), nil
 				}
@@ -766,6 +772,12 @@ var mathBuiltins = map[string]builtinDefinition{
 						"count must be greater than zero",
 					)
 				}
+				if b1 == b2 {
+					return nil, pgerror.New(
+						pgcode.InvalidArgumentForWidthBucketFunction,
+						"lower bound cannot equal upper bound",
+					)
+				}
 				return tree.NewDInt(tree.DInt(widthBucket(operand, b1, b2, count))), nil
 			},
 			Info: "return the bucket number to which operand would be assigned in a histogram having count " +