Honor the MATERIALIZED keyword on a common table expression by not flattening

the CTE into an outer query.

FossilOrigin-Name: 8d631a6b9eb06b54b10eda595a4c588ca38f909b4afa653b24d1f720b55d72f7

1 files changed, 5 insertions, 0 deletions

diff --git a/src/select.c b/src/select.c
index 2b27eea63..26a3172ae 100644
--- a/src/select.c
+++ b/src/select.c
@@ -4153,6 +4153,8 @@ static void renumberCursors(
 **  (27)  The subquery may not contain a FULL or RIGHT JOIN unless it
 **        is the first element of the parent query.
 **
+**  (28)  The subquery is not a MATERIALIZED CTE.
+**
 **
 ** In this routine, the "p" parameter is a pointer to the outer query.
 ** The subquery is p->pSrc->a[iFrom].  isAgg is true if the outer query
@@ -4276,6 +4278,9 @@ static int flattenSubquery(
   if( iFrom>0 && (pSubSrc->a[0].fg.jointype & JT_LTORJ)!=0 ){
     return 0;   /* Restriction (27) */
   }
+  if( pSubitem->fg.isCte && pSubitem->u2.pCteUse->eM10d==M10d_Yes ){
+    return 0;       /* (28) */
+  }
 
   /* Restriction (17): If the sub-query is a compound SELECT, then it must
   ** use only the UNION ALL operator. And none of the simple select queries