Add numeric_int8_opt_error() to optionally suppress errors

This matches the existing numeric_int4_opt_error() (see commit
16d489b0fe).  It will be used by a future JSON-related patch, which
wants to report errors in its own way and thus does not want the
internal functions to throw any error.

Author: Jeevan Chalke <jeevan.chalke@enterprisedb.com>
Discussion: https://www.postgresql.org/message-id/flat/CAM2+6=XjTyqrrqHAOj80r0wVQxJSxc0iyib9bPC55uFO9VKatg@mail.gmail.com

src/backend/utils/adt/numeric.c

@@ -4430,15 +4430,23 @@ int8_numeric(PG_FUNCTION_ARGS)
 	PG_RETURN_NUMERIC(int64_to_numeric(val));
 }
 
-
-Datum
-numeric_int8(PG_FUNCTION_ARGS)
+int64
+numeric_int8_opt_error(Numeric num, bool *have_error)
 {
-	Numeric		num = PG_GETARG_NUMERIC(0);
 	NumericVar	x;
 	int64		result;
 
+	if (have_error)
+		*have_error = false;
+
 	if (NUMERIC_IS_SPECIAL(num))
+	{
+		if (have_error)
+		{
+			*have_error = true;
+			return 0;
+		}
+		else
 		{
 			if (NUMERIC_IS_NAN(num))
 				ereport(ERROR,
@@ -4449,16 +4457,35 @@ numeric_int8(PG_FUNCTION_ARGS)
 						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 						 errmsg("cannot convert infinity to %s", "bigint")));
 		}
+	}
 
-	/* Convert to variable format and thence to int8 */
+	/* Convert to variable format, then convert to int8 */
 	init_var_from_num(num, &x);
 
 	if (!numericvar_to_int64(&x, &result))
+	{
+		if (have_error)
+		{
+			*have_error = true;
+			return 0;
+		}
+		else
+		{
 			ereport(ERROR,
 					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 					 errmsg("bigint out of range")));
+		}
+	}
+
+	return result;
+}
+
+Datum
+numeric_int8(PG_FUNCTION_ARGS)
+{
+	Numeric		num = PG_GETARG_NUMERIC(0);
 
-	PG_RETURN_INT64(result);
+	PG_RETURN_INT64(numeric_int8_opt_error(num, NULL));
 }
 
 

src/include/utils/numeric.h

@@ -101,5 +101,6 @@ extern Numeric numeric_div_opt_error(Numeric num1, Numeric num2,
 extern Numeric numeric_mod_opt_error(Numeric num1, Numeric num2,
 									 bool *have_error);
 extern int32 numeric_int4_opt_error(Numeric num, bool *have_error);
+extern int64 numeric_int8_opt_error(Numeric num, bool *have_error);
 
 #endif							/* _PG_NUMERIC_H_ */