WITH TIES: number of rows is optional and defaults to one

FETCH FIRST .. ONLY implements this correctly, but we missed to include
it for FETCH FIRST .. WITH TIES in commit 357889e.

Author: Vik Fearing
Discussion: https://postgr.es/m/6aa690ef-551d-e24f-2690-c38c2442947c@postgresfriends.org

Author: alvherre

src/backend/parser/gram.y

@@ -11816,6 +11816,14 @@ limit_clause:
 					n->limitOption = LIMIT_OPTION_COUNT;
 					$$ = n;
 				}
+			| FETCH first_or_next row_or_rows WITH TIES
+				{
+					SelectLimit *n = (SelectLimit *) palloc(sizeof(SelectLimit));
+					n->limitOffset = NULL;
+					n->limitCount = makeIntConst(1, -1);
+					n->limitOption = LIMIT_OPTION_WITH_TIES;
+					$$ = n;
+				}
 		;
 
 offset_clause:

src/test/regress/expected/limit.out

@@ -576,6 +576,23 @@ SELECT  thousand
         0
 (10 rows)
 
+SELECT  thousand
+		FROM onek WHERE thousand < 5
+		ORDER BY thousand FETCH FIRST ROWS WITH TIES;
+ thousand 
+----------
+        0
+        0
+        0
+        0
+        0
+        0
+        0
+        0
+        0
+        0
+(10 rows)
+
 SELECT  thousand
 		FROM onek WHERE thousand < 5
 		ORDER BY thousand FETCH FIRST 1 ROW WITH TIES;

src/test/regress/sql/limit.sql

@@ -161,13 +161,18 @@ SELECT  thousand
 		FROM onek WHERE thousand < 5
 		ORDER BY thousand FETCH FIRST 2 ROW WITH TIES;
 
+SELECT  thousand
+		FROM onek WHERE thousand < 5
+		ORDER BY thousand FETCH FIRST ROWS WITH TIES;
+
 SELECT  thousand
 		FROM onek WHERE thousand < 5
 		ORDER BY thousand FETCH FIRST 1 ROW WITH TIES;
 
 SELECT  thousand
 		FROM onek WHERE thousand < 5
 		ORDER BY thousand FETCH FIRST 2 ROW ONLY;
+
 -- should fail
 SELECT ''::text AS two, unique1, unique2, stringu1
 		FROM onek WHERE unique1 > 50