1 files changed, 11 insertions, 15 deletions

diff --git a/src/backup.c b/src/backup.c
index 77e7ed950..22615d149 100644
--- a/src/backup.c
+++ b/src/backup.c
@@ -85,14 +85,13 @@ static Btree *findBtree(sqlite3 *pErrorDb, sqlite3 *pDb, const char *zDb){
   if( i==1 ){
     Parse sParse;
     int rc = 0;
-    memset(&sParse, 0, sizeof(sParse));
-    sParse.db = pDb;
+    sqlite3ParseObjectInit(&sParse,pDb);
     if( sqlite3OpenTempDatabase(&sParse) ){
       sqlite3ErrorWithMsg(pErrorDb, sParse.rc, "%s", sParse.zErrMsg);
       rc = SQLITE_ERROR;
     }
     sqlite3DbFree(pErrorDb, sParse.zErrMsg);
-    sqlite3ParserReset(&sParse);
+    sqlite3ParseObjectReset(&sParse);
     if( rc ){
       return 0;
     }
@@ -123,7 +122,7 @@ static int setDestPgsz(sqlite3_backup *p){
 ** message in database handle db.
 */
 static int checkReadTransaction(sqlite3 *db, Btree *p){
-  if( sqlite3BtreeIsInReadTrans(p) ){
+  if( sqlite3BtreeTxnState(p)!=SQLITE_TXN_NONE ){
     sqlite3ErrorWithMsg(db, SQLITE_ERROR, "destination database is in use");
     return SQLITE_ERROR;
   }
@@ -243,13 +242,7 @@ static int backupOnePage(
   assert( !isFatalError(p->rc) );
   assert( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) );
   assert( zSrcData );
-
-  /* Catch the case where the destination is an in-memory database and the
-  ** page sizes of the source and destination differ. 
-  */
-  if( nSrcPgsz!=nDestPgsz && sqlite3PagerIsMemdb(pDestPager) ){
-    rc = SQLITE_READONLY;
-  }
+  assert( nSrcPgsz==nDestPgsz || sqlite3PagerIsMemdb(pDestPager)==0 );
 
   /* This loop runs once for each destination page spanned by the source 
   ** page. For each iteration, variable iOff is set to the byte offset
@@ -354,7 +347,7 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
     ** one now. If a transaction is opened here, then it will be closed
     ** before this function exits.
     */
-    if( rc==SQLITE_OK && 0==sqlite3BtreeIsInReadTrans(p->pSrc) ){
+    if( rc==SQLITE_OK && SQLITE_TXN_NONE==sqlite3BtreeTxnState(p->pSrc) ){
       rc = sqlite3BtreeBeginTrans(p->pSrc, 0, 0);
       bCloseTrans = 1;
     }
@@ -382,7 +375,10 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
     pgszSrc = sqlite3BtreeGetPageSize(p->pSrc);
     pgszDest = sqlite3BtreeGetPageSize(p->pDest);
     destMode = sqlite3PagerGetJournalMode(sqlite3BtreePager(p->pDest));
-    if( SQLITE_OK==rc && destMode==PAGER_JOURNALMODE_WAL && pgszSrc!=pgszDest ){
+    if( SQLITE_OK==rc 
+     && (destMode==PAGER_JOURNALMODE_WAL || sqlite3PagerIsMemdb(pDestPager))
+     && pgszSrc!=pgszDest 
+    ){
       rc = SQLITE_READONLY;
     }
   
@@ -726,7 +722,7 @@ int sqlite3BtreeCopyFile(Btree *pTo, Btree *pFrom){
   sqlite3BtreeEnter(pTo);
   sqlite3BtreeEnter(pFrom);
 
-  assert( sqlite3BtreeIsInTrans(pTo) );
+  assert( sqlite3BtreeTxnState(pTo)==SQLITE_TXN_WRITE );
   pFd = sqlite3PagerFile(sqlite3BtreePager(pTo));
   if( pFd->pMethods ){
     i64 nByte = sqlite3BtreeGetPageSize(pFrom)*(i64)sqlite3BtreeLastPage(pFrom);
@@ -762,7 +758,7 @@ int sqlite3BtreeCopyFile(Btree *pTo, Btree *pFrom){
     sqlite3PagerClearCache(sqlite3BtreePager(b.pDest));
   }
 
-  assert( sqlite3BtreeIsInTrans(pTo)==0 );
+  assert( sqlite3BtreeTxnState(pTo)!=SQLITE_TXN_WRITE );
 copy_finished:
   sqlite3BtreeLeave(pFrom);
   sqlite3BtreeLeave(pTo);