Fix the OP_OpenDup opcode so that it is able to duplicate a cursor that

was itself opened by OP_OpenDup.  Add additional verification of
ephemeral tables.  Fix for ticket [bb8a9fd4a9b7fce5].

FossilOrigin-Name: bcbe5308f3a3b94f965b0f5627cb29cce2e09343b86d757e2de889f7773576e7

1 files changed, 19 insertions, 8 deletions

diff --git a/src/btree.c b/src/btree.c
index 500421ac0..1623e0172 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -2737,19 +2737,23 @@ static void freeTempSpace(BtShared *pBt){
 */
 int sqlite3BtreeClose(Btree *p){
   BtShared *pBt = p->pBt;
-  BtCursor *pCur;
 
   /* Close all cursors opened via this handle.  */
   assert( sqlite3_mutex_held(p->db->mutex) );
   sqlite3BtreeEnter(p);
-  pCur = pBt->pCursor;
-  while( pCur ){
-    BtCursor *pTmp = pCur;
-    pCur = pCur->pNext;
-    if( pTmp->pBtree==p ){
-      sqlite3BtreeCloseCursor(pTmp);
+
+  /* Verify that no other cursors have this Btree open */
+#ifdef SQLITE_DEBUG
+  {
+    BtCursor *pCur = pBt->pCursor;
+    while( pCur ){
+      BtCursor *pTmp = pCur;
+      pCur = pCur->pNext;
+      assert( pTmp->pBtree!=p );
+
     }
   }
+#endif
 
   /* Rollback any active transaction and free the handle structure.
   ** The call to sqlite3BtreeRollback() drops any table-locks held by
@@ -4541,7 +4545,14 @@ int sqlite3BtreeCloseCursor(BtCursor *pCur){
     unlockBtreeIfUnused(pBt);
     sqlite3_free(pCur->aOverflow);
     sqlite3_free(pCur->pKey);
-    sqlite3BtreeLeave(pBtree);
+    if( (pBt->openFlags & BTREE_SINGLE) && pBt->pCursor==0 ){
+      /* Since the BtShared is not sharable, there is no need to
+      ** worry about the missing sqlite3BtreeLeave() call here.  */
+      assert( pBtree->sharable==0 );
+      sqlite3BtreeClose(pBtree);
+    }else{
+      sqlite3BtreeLeave(pBtree);
+    }
     pCur->pBtree = 0;
   }
   return SQLITE_OK;