Fix issue apache#2353: Incorrect canonicalization of NATURAL JOIN (apache#2355)

Author: revitalkr

src/parser/mod.rs

@@ -15994,6 +15994,7 @@ impl<'a> Parser<'a> {
                 if !self
                     .dialect
                     .supports_left_associative_joins_without_parens()
+                    && !natural
                     && self.peek_parens_less_nested_join()
                 {
                     let joins = self.parse_joins()?;

tests/sqlparser_common.rs

@@ -17443,8 +17443,7 @@ fn column_check_enforced() {
 
 #[test]
 fn join_precedence() {
-    all_dialects_except(|d| !d.supports_left_associative_joins_without_parens())
-        .verified_query_with_canonical(
+    all_dialects().verified_query_with_canonical(
         "SELECT *
          FROM t1
          NATURAL JOIN t5
@@ -17453,15 +17452,6 @@ fn join_precedence() {
         // canonical string without parentheses
         "SELECT * FROM t1 NATURAL JOIN t5 INNER JOIN t0 ON (t0.v1 + t5.v0) > 0 WHERE t0.v1 = t1.v0",
     );
-    all_dialects_except(|d| d.supports_left_associative_joins_without_parens()).verified_query_with_canonical(
-        "SELECT *
-         FROM t1
-         NATURAL JOIN t5
-         INNER JOIN t0 ON (t0.v1 + t5.v0) > 0
-         WHERE t0.v1 = t1.v0",
-        // canonical string with parentheses
-        "SELECT * FROM t1 NATURAL JOIN (t5 INNER JOIN t0 ON (t0.v1 + t5.v0) > 0) WHERE t0.v1 = t1.v0",
-    );
 }
 
 #[test]