Update the sessions branch to the latest 3.7.17 beta.

FossilOrigin-Name: af8057ef5dcaa72dc0d2ab5d1553b06757449fa1

1 files changed, 14 insertions, 6 deletions

diff --git a/src/main.c b/src/main.c
index d53503aec..39ef5bfb5 100644
--- a/src/main.c
+++ b/src/main.c
@@ -848,12 +848,6 @@ static int sqlite3Close(sqlite3 *db, int forceZombie){
     return SQLITE_BUSY;
   }
 
-  /* If a transaction is open, roll it back. This also ensures that if
-  ** any database schemas have been modified by the current transaction
-  ** they are reset. And that the required b-tree mutex is held to make
-  ** the the pager rollback and schema reset an atomic operation. */
-  sqlite3RollbackAll(db, SQLITE_OK);
-
 #ifdef SQLITE_ENABLE_SQLLOG
   if( sqlite3GlobalConfig.xSqllog ){
     /* Closing the handle. Fourth parameter is passed the value 2. */
@@ -908,6 +902,12 @@ void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
   ** go ahead and free all resources.
   */
 
+  /* If a transaction is open, roll it back. This also ensures that if
+  ** any database schemas have been modified by an uncommitted transaction
+  ** they are reset. And that the required b-tree mutex is held to make
+  ** the pager rollback and schema reset an atomic operation. */
+  sqlite3RollbackAll(db, SQLITE_OK);
+
   /* Free any outstanding Savepoint structures. */
   sqlite3CloseSavepoints(db);
 
@@ -1008,7 +1008,15 @@ void sqlite3RollbackAll(sqlite3 *db, int tripCode){
   int inTrans = 0;
   assert( sqlite3_mutex_held(db->mutex) );
   sqlite3BeginBenignMalloc();
+
+  /* Obtain all b-tree mutexes before making any calls to BtreeRollback(). 
+  ** This is important in case the transaction being rolled back has
+  ** modified the database schema. If the b-tree mutexes are not taken
+  ** here, then another shared-cache connection might sneak in between
+  ** the database rollback and schema reset, which can cause false
+  ** corruption reports in some cases.  */
   sqlite3BtreeEnterAll(db);
+
   for(i=0; i<db->nDb; i++){
     Btree *p = db->aDb[i].pBt;
     if( p ){