DISTINCT may not be ignored inside a UNION ALL common table expression.

Fix for ticket [c51489c3b8f919c5]

FossilOrigin-Name: 7d2b590d3abd66a7e6ae9046198eb669e0fd2f223f7691281e9ad795a12b8903

2 files changed, 14 insertions, 14 deletions

diff --git a/src/select.c b/src/select.c
index 9568dbadc..535f883a1 100644
--- a/src/select.c
+++ b/src/select.c
@@ -5808,13 +5808,11 @@ int sqlite3Select(
   assert( p->pOrderBy==0 || pDest->eDest!=SRT_Fifo );
   assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistQueue );
   assert( p->pOrderBy==0 || pDest->eDest!=SRT_Queue );
-  if( IgnorableOrderby(pDest) ){
-    assert(pDest->eDest==SRT_Exists || pDest->eDest==SRT_Union || 
-           pDest->eDest==SRT_Except || pDest->eDest==SRT_Discard ||
-           pDest->eDest==SRT_Queue  || pDest->eDest==SRT_DistFifo ||
-           pDest->eDest==SRT_DistQueue || pDest->eDest==SRT_Fifo);
-    /* If ORDER BY makes no difference in the output then neither does
-    ** DISTINCT so it can be removed too. */
+  if( IgnorableDistinct(pDest) ){
+    assert(pDest->eDest==SRT_Exists     || pDest->eDest==SRT_Union || 
+           pDest->eDest==SRT_Except     || pDest->eDest==SRT_Discard ||
+           pDest->eDest==SRT_DistQueue  || pDest->eDest==SRT_DistFifo );
+    /* All of these destinations are also able to ignore the ORDER BY clause */
     sqlite3ExprListDelete(db, p->pOrderBy);
     p->pOrderBy = 0;
     p->selFlags &= ~SF_Distinct;
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 9afc287a5..ec832eca6 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3152,9 +3152,6 @@ struct Select {
 **                     statements within triggers whose only purpose is
 **                     the side-effects of functions.
 **
-** All of the above are free to ignore their ORDER BY clause. Those that
-** follow must honor the ORDER BY clause.
-**
 **     SRT_Output      Generate a row of output (using the OP_ResultRow
 **                     opcode) for each row in the result set.
 **
@@ -3211,13 +3208,18 @@ struct Select {
 #define SRT_Except       2  /* Remove result from a UNION index */
 #define SRT_Exists       3  /* Store 1 if the result is not empty */
 #define SRT_Discard      4  /* Do not save the results anywhere */
-#define SRT_Fifo         5  /* Store result as data with an automatic rowid */
-#define SRT_DistFifo     6  /* Like SRT_Fifo, but unique results only */
+#define SRT_DistFifo     5  /* Like SRT_Fifo, but unique results only */
+#define SRT_DistQueue    6  /* Like SRT_Queue, but unique results only */
+
+/* The DISTINCT clause is ignored for all of the above.  Not that
+** IgnorableDistinct() implies IgnorableOrderby() */
+#define IgnorableDistinct(X) ((X->eDest)<=SRT_DistQueue)
+
 #define SRT_Queue        7  /* Store result in an queue */
-#define SRT_DistQueue    8  /* Like SRT_Queue, but unique results only */
+#define SRT_Fifo         8  /* Store result as data with an automatic rowid */
 
 /* The ORDER BY clause is ignored for all of the above */
-#define IgnorableOrderby(X) ((X->eDest)<=SRT_DistQueue)
+#define IgnorableOrderby(X) ((X->eDest)<=SRT_Fifo)
 
 #define SRT_Output       9  /* Output each row of result */
 #define SRT_Mem         10  /* Store result in a memory cell */