1 files changed, 23 insertions, 6 deletions

diff --git a/src/backup.c b/src/backup.c
index da4303e5f..e3f869035 100644
--- a/src/backup.c
+++ b/src/backup.c
@@ -123,6 +123,20 @@ static int setDestPgsz(sqlite3_backup *p){
 }
 
 /*
+** Check that there is no open read-transaction on the b-tree passed as the
+** second argument. If there is not, return SQLITE_OK. Otherwise, if there
+** is an open read-transaction, return SQLITE_ERROR and leave an error 
+** message in database handle db.
+*/
+static int checkReadTransaction(sqlite3 *db, Btree *p){
+  if( sqlite3BtreeIsInReadTrans(p) ){
+    sqlite3ErrorWithMsg(db, SQLITE_ERROR, "destination database is in use");
+    return SQLITE_ERROR;
+  }
+  return SQLITE_OK;
+}
+
+/*
 ** Create an sqlite3_backup process to copy the contents of zSrcDb from
 ** connection handle pSrcDb to zDestDb in pDestDb. If successful, return
 ** a pointer to the new sqlite3_backup object.
@@ -181,12 +195,15 @@ sqlite3_backup *sqlite3_backup_init(
     p->iNext = 1;
     p->isAttached = 0;
 
-    if( 0==p->pSrc || 0==p->pDest || setDestPgsz(p)==SQLITE_NOMEM ){
+    if( 0==p->pSrc || 0==p->pDest 
+     || setDestPgsz(p)==SQLITE_NOMEM 
+     || checkReadTransaction(pDestDb, p->pDest)!=SQLITE_OK 
+     ){
       /* One (or both) of the named databases did not exist or an OOM
-      ** error was hit.  The error has already been written into the
-      ** pDestDb handle.  All that is left to do here is free the
-      ** sqlite3_backup structure.
-      */
+      ** error was hit. Or there is a transaction open on the destination
+      ** database. The error has already been written into the pDestDb 
+      ** handle. All that is left to do here is free the sqlite3_backup 
+      ** structure.  */
       sqlite3_free(p);
       p = 0;
     }
@@ -607,7 +624,7 @@ int sqlite3_backup_finish(sqlite3_backup *p){
   }
 
   /* If a transaction is still open on the Btree, roll it back. */
-  sqlite3BtreeRollback(p->pDest, SQLITE_OK);
+  sqlite3BtreeRollback(p->pDest, SQLITE_OK, 0);
 
   /* Set the error code of the destination database handle. */
   rc = (p->rc==SQLITE_DONE) ? SQLITE_OK : p->rc;