Reject out-of-range dates in to_date().

Dates outside the supported range could be entered, but would not print
reasonably, and operations such as conversion to timestamp wouldn't behave
sanely either.  Since this has the potential to result in undumpable table
data, it seems worth back-patching.

Hitoshi Harada

src/backend/utils/adt/formatting.c

@@ -3079,6 +3079,12 @@ to_date(PG_FUNCTION_ARGS)
 
 	do_to_timestamp(date_txt, fmt, &tm, &fsec);
 
+	if (!IS_VALID_JULIAN(tm.tm_year, tm.tm_mon, tm.tm_mday))
+		ereport(ERROR,
+				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+				 errmsg("date out of range: \"%s\"",
+						text_to_cstring(date_txt))));
+
 	result = date2j(tm.tm_year, tm.tm_mon, tm.tm_mday) - POSTGRES_EPOCH_JDATE;
 
 	PG_RETURN_DATEADT(result);