1 files changed, 30 insertions, 7 deletions

diff --git a/ext/rbu/sqlite3rbu.c b/ext/rbu/sqlite3rbu.c
index 235ba3fe2..48c69115e 100644
--- a/ext/rbu/sqlite3rbu.c
+++ b/ext/rbu/sqlite3rbu.c
@@ -2333,7 +2333,7 @@ static RbuState *rbuLoadState(sqlite3rbu *p){
 ** Open the database handle and attach the RBU database as "rbu". If an
 ** error occurs, leave an error code and message in the RBU handle.
 */
-static void rbuOpenDatabase(sqlite3rbu *p){
+static void rbuOpenDatabase(sqlite3rbu *p, int *pbRetry){
   assert( p->rc || (p->dbMain==0 && p->dbRbu==0) );
   assert( p->rc || rbuIsVacuum(p) || p->zTarget!=0 );
 
@@ -2420,6 +2420,15 @@ static void rbuOpenDatabase(sqlite3rbu *p){
     if( !rbuIsVacuum(p) ){
       p->dbMain = rbuOpenDbhandle(p, p->zTarget, 1);
     }else if( p->pRbuFd->pWalFd ){
+      if( pbRetry ){
+        p->pRbuFd->bNolock = 0;
+        sqlite3_close(p->dbRbu);
+        sqlite3_close(p->dbMain);
+        p->dbMain = 0;
+        p->dbRbu = 0;
+        *pbRetry = 1;
+        return;
+      }
       p->rc = SQLITE_ERROR;
       p->zErrmsg = sqlite3_mprintf("cannot vacuum wal mode database");
     }else{
@@ -2600,16 +2609,18 @@ static void rbuSetupCheckpoint(sqlite3rbu *p, RbuState *pState){
     if( rc2!=SQLITE_INTERNAL ) p->rc = rc2;
   }
 
-  if( p->rc==SQLITE_OK ){
+  if( p->rc==SQLITE_OK && p->nFrame>0 ){
     p->eStage = RBU_STAGE_CKPT;
     p->nStep = (pState ? pState->nRow : 0);
     p->aBuf = rbuMalloc(p, p->pgsz);
     p->iWalCksum = rbuShmChecksum(p);
   }
 
-  if( p->rc==SQLITE_OK && pState && pState->iWalCksum!=p->iWalCksum ){
-    p->rc = SQLITE_DONE;
-    p->eStage = RBU_STAGE_DONE;
+  if( p->rc==SQLITE_OK ){
+    if( p->nFrame==0 || (pState && pState->iWalCksum!=p->iWalCksum) ){
+      p->rc = SQLITE_DONE;
+      p->eStage = RBU_STAGE_DONE;
+    }
   }
 }
 
@@ -2782,7 +2793,7 @@ static void rbuMoveOalFile(sqlite3rbu *p){
 #endif
 
       if( p->rc==SQLITE_OK ){
-        rbuOpenDatabase(p);
+        rbuOpenDatabase(p, 0);
         rbuSetupCheckpoint(p, 0);
       }
     }
@@ -3493,6 +3504,7 @@ static sqlite3rbu *openRbuHandle(
     /* Open the target, RBU and state databases */
     if( p->rc==SQLITE_OK ){
       char *pCsr = (char*)&p[1];
+      int bRetry = 0;
       if( zTarget ){
         p->zTarget = pCsr;
         memcpy(p->zTarget, zTarget, nTarget+1);
@@ -3504,7 +3516,18 @@ static sqlite3rbu *openRbuHandle(
       if( zState ){
         p->zState = rbuMPrintf(p, "%s", zState);
       }
-      rbuOpenDatabase(p);
+
+      /* If the first attempt to open the database file fails and the bRetry
+      ** flag it set, this means that the db was not opened because it seemed
+      ** to be a wal-mode db. But, this may have happened due to an earlier
+      ** RBU vacuum operation leaving an old wal file in the directory.
+      ** If this is the case, it will have been checkpointed and deleted
+      ** when the handle was closed and a second attempt to open the 
+      ** database may succeed.  */
+      rbuOpenDatabase(p, &bRetry);
+      if( bRetry ){
+        rbuOpenDatabase(p, 0);
+      }
     }
 
     if( p->rc==SQLITE_OK ){