As long as we're forcing an ORDER BY in these four join queries, we had

better make sure the sort order is totally specified; else we get burnt
by platform-specific behavior of qsort() with equal keys.  Per buildfarm
results.

src/test/regress/expected/join.out

@@ -1718,7 +1718,7 @@ SELECT '' AS "xxx", *
 --
 SELECT '' AS "xxx", *
   FROM J1_TBL LEFT OUTER JOIN J2_TBL USING (i)
-  ORDER BY i, k;
+  ORDER BY i, k, t;
  xxx | i | j |   t   | k  
 -----+---+---+-------+----
      | 0 |   | zero  |   
@@ -1738,7 +1738,7 @@ SELECT '' AS "xxx", *
 
 SELECT '' AS "xxx", *
   FROM J1_TBL LEFT JOIN J2_TBL USING (i)
-  ORDER BY i, k;
+  ORDER BY i, k, t;
  xxx | i | j |   t   | k  
 -----+---+---+-------+----
      | 0 |   | zero  |   
@@ -1788,7 +1788,7 @@ SELECT '' AS "xxx", *
 
 SELECT '' AS "xxx", *
   FROM J1_TBL FULL OUTER JOIN J2_TBL USING (i)
-  ORDER BY i, k;
+  ORDER BY i, k, t;
  xxx | i | j |   t   | k  
 -----+---+---+-------+----
      | 0 |   | zero  |   
@@ -1810,7 +1810,7 @@ SELECT '' AS "xxx", *
 
 SELECT '' AS "xxx", *
   FROM J1_TBL FULL JOIN J2_TBL USING (i)
-  ORDER BY i, k;
+  ORDER BY i, k, t;
  xxx | i | j |   t   | k  
 -----+---+---+-------+----
      | 0 |   | zero  |   

src/test/regress/sql/join.sql

@@ -167,11 +167,11 @@ SELECT '' AS "xxx", *
 
 SELECT '' AS "xxx", *
   FROM J1_TBL LEFT OUTER JOIN J2_TBL USING (i)
-  ORDER BY i, k;
+  ORDER BY i, k, t;
 
 SELECT '' AS "xxx", *
   FROM J1_TBL LEFT JOIN J2_TBL USING (i)
-  ORDER BY i, k;
+  ORDER BY i, k, t;
 
 SELECT '' AS "xxx", *
   FROM J1_TBL RIGHT OUTER JOIN J2_TBL USING (i);
@@ -181,11 +181,11 @@ SELECT '' AS "xxx", *
 
 SELECT '' AS "xxx", *
   FROM J1_TBL FULL OUTER JOIN J2_TBL USING (i)
-  ORDER BY i, k;
+  ORDER BY i, k, t;
 
 SELECT '' AS "xxx", *
   FROM J1_TBL FULL JOIN J2_TBL USING (i)
-  ORDER BY i, k;
+  ORDER BY i, k, t;
 
 SELECT '' AS "xxx", *
   FROM J1_TBL LEFT JOIN J2_TBL USING (i) WHERE (k = 1);