1 files changed, 10 insertions, 4 deletions
diff --git a/src/build.c b/src/build.c
index 27d7b499d..5495cef18 100644
--- a/src/build.c
+++ b/src/build.c
@@ -5137,16 +5137,22 @@ void sqlite3SrcListIndexedBy(Parse *pParse, SrcList *p, Token *pIndexedBy){
 ** are deleted by this function.
 */
 SrcList *sqlite3SrcListAppendList(Parse *pParse, SrcList *p1, SrcList *p2){
-  assert( p1 && p1->nSrc==1 );
+  assert( p1 );
+  assert( p2 || pParse->nErr );
+  assert( p2==0 || p2->nSrc>=1 );
+  testcase( p1->nSrc==0 );
   if( p2 ){
-    SrcList *pNew = sqlite3SrcListEnlarge(pParse, p1, p2->nSrc, 1);
+    int nOld = p1->nSrc;
+    SrcList *pNew = sqlite3SrcListEnlarge(pParse, p1, p2->nSrc, nOld);
     if( pNew==0 ){
       sqlite3SrcListDelete(pParse->db, p2);
     }else{
       p1 = pNew;
-      memcpy(&p1->a[1], p2->a, p2->nSrc*sizeof(SrcItem));
+      memcpy(&p1->a[nOld], p2->a, p2->nSrc*sizeof(SrcItem));
+      assert( nOld==1 || (p2->a[0].fg.jointype & JT_LTORJ)==0 );
+      assert( p1->nSrc>=1 );
+      p1->a[0].fg.jointype |= (JT_LTORJ & p2->a[0].fg.jointype);
       sqlite3DbFree(pParse->db, p2);
-      p1->a[0].fg.jointype |= (JT_LTORJ & p1->a[1].fg.jointype);
     }
   }
   return p1;