Do not allow triggers that run as part of REPLACE conflict resolution

during an UPDATE to modify the the table being updated.  Otherwise, those
triggers might delete content out from under the update operation, leading
to all kinds of problems.  Ticket [314cc133e5ada126]

FossilOrigin-Name: db4b7e1dc399c1f16b827ac087aa37c0815f4b2f41f1ffad59963eead2ab5562

1 files changed, 15 insertions, 0 deletions

diff --git a/src/btree.c b/src/btree.c
index eb80816bb..a137da3c7 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -699,6 +699,9 @@ static int saveCursorPosition(BtCursor *pCur){
   assert( 0==pCur->pKey );
   assert( cursorHoldsMutex(pCur) );
 
+  if( pCur->curFlags & BTCF_Pinned ){
+    return SQLITE_CONSTRAINT_PINNED;
+  }
   if( pCur->eState==CURSOR_SKIPNEXT ){
     pCur->eState = CURSOR_VALID;
   }else{
@@ -4562,6 +4565,18 @@ i64 sqlite3BtreeIntegerKey(BtCursor *pCur){
   return pCur->info.nKey;
 }
 
+/*
+** Pin or unpin a cursor.
+*/
+void sqlite3BtreeCursorPin(BtCursor *pCur){
+  assert( (pCur->curFlags & BTCF_Pinned)==0 );
+  pCur->curFlags |= BTCF_Pinned;
+}
+void sqlite3BtreeCursorUnpin(BtCursor *pCur){
+  assert( (pCur->curFlags & BTCF_Pinned)!=0 );
+  pCur->curFlags &= ~BTCF_Pinned;
+}
+
 #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC
 /*
 ** Return the offset into the database file for the start of the