1 files changed, 75 insertions, 0 deletions
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 5b34badd5bc..6f400729713 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -2165,6 +2165,81 @@ cmp_numerics(Numeric num1, Numeric num2)
 	return result;
 }
 
+/*
+ * in_range support function for numeric.
+ */
+Datum
+in_range_numeric_numeric(PG_FUNCTION_ARGS)
+{
+	Numeric		val = PG_GETARG_NUMERIC(0);
+	Numeric		base = PG_GETARG_NUMERIC(1);
+	Numeric		offset = PG_GETARG_NUMERIC(2);
+	bool		sub = PG_GETARG_BOOL(3);
+	bool		less = PG_GETARG_BOOL(4);
+	bool		result;
+
+	/*
+	 * Reject negative or NaN offset.  Negative is per spec, and NaN is
+	 * because appropriate semantics for that seem non-obvious.
+	 */
+	if (NUMERIC_IS_NAN(offset) || NUMERIC_SIGN(offset) == NUMERIC_NEG)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PRECEDING_FOLLOWING_SIZE),
+				 errmsg("invalid preceding or following size in window function")));
+
+	/*
+	 * Deal with cases where val and/or base is NaN, following the rule that
+	 * NaN sorts after non-NaN (cf cmp_numerics).  The offset cannot affect
+	 * the conclusion.
+	 */
+	if (NUMERIC_IS_NAN(val))
+	{
+		if (NUMERIC_IS_NAN(base))
+			result = true;		/* NAN = NAN */
+		else
+			result = !less;		/* NAN > non-NAN */
+	}
+	else if (NUMERIC_IS_NAN(base))
+	{
+		result = less;			/* non-NAN < NAN */
+	}
+	else
+	{
+		/*
+		 * Otherwise go ahead and compute base +/- offset.  While it's
+		 * possible for this to overflow the numeric format, it's unlikely
+		 * enough that we don't take measures to prevent it.
+		 */
+		NumericVar	valv;
+		NumericVar	basev;
+		NumericVar	offsetv;
+		NumericVar	sum;
+
+		init_var_from_num(val, &valv);
+		init_var_from_num(base, &basev);
+		init_var_from_num(offset, &offsetv);
+		init_var(&sum);
+
+		if (sub)
+			sub_var(&basev, &offsetv, &sum);
+		else
+			add_var(&basev, &offsetv, &sum);
+
+		if (less)
+			result = (cmp_var(&valv, &sum) <= 0);
+		else
+			result = (cmp_var(&valv, &sum) >= 0);
+
+		free_var(&sum);
+	}
+
+	PG_FREE_IF_COPY(val, 0);
+	PG_FREE_IF_COPY(base, 1);
+	PG_FREE_IF_COPY(offset, 2);
+
+	PG_RETURN_BOOL(result);
+}
+
 Datum
 hash_numeric(PG_FUNCTION_ARGS)
 {