1 files changed, 41 insertions, 30 deletions

diff --git a/src/memjournal.c b/src/memjournal.c
index 0a14e847a..934380107 100644
--- a/src/memjournal.c
+++ b/src/memjournal.c
@@ -70,7 +70,6 @@ struct MemJournal {
   int nChunkSize;                 /* In-memory chunk-size */
 
   int nSpill;                     /* Bytes of data before flushing */
-  int nSize;                      /* Bytes of data currently in memory */
   FileChunk *pFirst;              /* Head of in-memory chunk-list */
   FilePoint endpoint;             /* Pointer to the end of the file */
   FilePoint readpoint;            /* Pointer to the end of the last xRead() */
@@ -131,14 +130,13 @@ static int memjrnlRead(
 /*
 ** Free the list of FileChunk structures headed at MemJournal.pFirst.
 */
-static void memjrnlFreeChunks(MemJournal *p){
+static void memjrnlFreeChunks(FileChunk *pFirst){
   FileChunk *pIter;
   FileChunk *pNext;
-  for(pIter=p->pFirst; pIter; pIter=pNext){
+  for(pIter=pFirst; pIter; pIter=pNext){
     pNext = pIter->pNext;
     sqlite3_free(pIter);
   } 
-  p->pFirst = 0;
 }
 
 /*
@@ -165,7 +163,7 @@ static int memjrnlCreateFile(MemJournal *p){
     }
     if( rc==SQLITE_OK ){
       /* No error has occurred. Free the in-memory buffers. */
-      memjrnlFreeChunks(&copy);
+      memjrnlFreeChunks(copy.pFirst);
     }
   }
   if( rc!=SQLITE_OK ){
@@ -180,6 +178,9 @@ static int memjrnlCreateFile(MemJournal *p){
 }
 
 
+/* Forward reference */
+static int memjrnlTruncate(sqlite3_file *pJfd, sqlite_int64 size);
+
 /*
 ** Write data to the file.
 */
@@ -209,23 +210,21 @@ static int memjrnlWrite(
     ** access writes are not required. The only exception to this is when
     ** the in-memory journal is being used by a connection using the
     ** atomic-write optimization. In this case the first 28 bytes of the
-    ** journal file may be written as part of committing the transaction. */ 
-    assert( iOfst==p->endpoint.iOffset || iOfst==0 );
-#if defined(SQLITE_ENABLE_ATOMIC_WRITE) \
- || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE)
+    ** journal file may be written as part of committing the transaction. */
+    assert( iOfst<=p->endpoint.iOffset );
+    if( iOfst>0 && iOfst!=p->endpoint.iOffset ){
+      memjrnlTruncate(pJfd, iOfst);
+    }
     if( iOfst==0 && p->pFirst ){
       assert( p->nChunkSize>iAmt );
       memcpy((u8*)p->pFirst->zChunk, zBuf, iAmt);
-    }else
-#else
-    assert( iOfst>0 || p->pFirst==0 );
-#endif
-    {
+    }else{
       while( nWrite>0 ){
         FileChunk *pChunk = p->endpoint.pChunk;
         int iChunkOffset = (int)(p->endpoint.iOffset%p->nChunkSize);
         int iSpace = MIN(nWrite, p->nChunkSize - iChunkOffset);
 
+        assert( pChunk!=0 || iChunkOffset==0 );
         if( iChunkOffset==0 ){
           /* New chunk is required to extend the file. */
           FileChunk *pNew = sqlite3_malloc(fileChunkSize(p->nChunkSize));
@@ -240,15 +239,15 @@ static int memjrnlWrite(
             assert( !p->pFirst );
             p->pFirst = pNew;
           }
-          p->endpoint.pChunk = pNew;
+          pChunk = p->endpoint.pChunk = pNew;
         }
 
-        memcpy((u8*)p->endpoint.pChunk->zChunk + iChunkOffset, zWrite, iSpace);
+        assert( pChunk!=0 );
+        memcpy((u8*)pChunk->zChunk + iChunkOffset, zWrite, iSpace);
         zWrite += iSpace;
         nWrite -= iSpace;
         p->endpoint.iOffset += iSpace;
       }
-      p->nSize = iAmt + iOfst;
     }
   }
 
@@ -256,19 +255,29 @@ static int memjrnlWrite(
 }
 
 /*
-** Truncate the file.
-**
-** If the journal file is already on disk, truncate it there. Or, if it
-** is still in main memory but is being truncated to zero bytes in size,
-** ignore 
+** Truncate the in-memory file.
 */
 static int memjrnlTruncate(sqlite3_file *pJfd, sqlite_int64 size){
   MemJournal *p = (MemJournal *)pJfd;
-  if( ALWAYS(size==0) ){
-    memjrnlFreeChunks(p);
-    p->nSize = 0;
-    p->endpoint.pChunk = 0;
-    p->endpoint.iOffset = 0;
+  assert( p->endpoint.pChunk==0 || p->endpoint.pChunk->pNext==0 );
+  if( size<p->endpoint.iOffset ){
+    FileChunk *pIter = 0;
+    if( size==0 ){
+      memjrnlFreeChunks(p->pFirst);
+      p->pFirst = 0;
+    }else{
+      i64 iOff = p->nChunkSize;
+      for(pIter=p->pFirst; ALWAYS(pIter) && iOff<size; pIter=pIter->pNext){
+        iOff += p->nChunkSize;
+      }
+      if( ALWAYS(pIter) ){
+        memjrnlFreeChunks(pIter->pNext);
+        pIter->pNext = 0;
+      }
+    }
+
+    p->endpoint.pChunk = pIter;
+    p->endpoint.iOffset = size;
     p->readpoint.pChunk = 0;
     p->readpoint.iOffset = 0;
   }
@@ -280,7 +289,7 @@ static int memjrnlTruncate(sqlite3_file *pJfd, sqlite_int64 size){
 */
 static int memjrnlClose(sqlite3_file *pJfd){
   MemJournal *p = (MemJournal *)pJfd;
-  memjrnlFreeChunks(p);
+  memjrnlFreeChunks(p->pFirst);
   return SQLITE_OK;
 }
 
@@ -350,6 +359,8 @@ int sqlite3JournalOpen(
 ){
   MemJournal *p = (MemJournal*)pJfd;
 
+  assert( zName || nSpill<0 || (flags & SQLITE_OPEN_EXCLUSIVE) );
+
   /* Zero the file-handle object. If nSpill was passed zero, initialize
   ** it using the sqlite3OsOpen() function of the underlying VFS. In this
   ** case none of the code in this module is executed as a result of calls
@@ -366,7 +377,7 @@ int sqlite3JournalOpen(
     assert( MEMJOURNAL_DFLT_FILECHUNKSIZE==fileChunkSize(p->nChunkSize) );
   }
 
-  p->pMethod = (const sqlite3_io_methods*)&MemJournalMethods;
+  pJfd->pMethods = (const sqlite3_io_methods*)&MemJournalMethods;
   p->nSpill = nSpill;
   p->flags = flags;
   p->zJournal = zName;
@@ -392,7 +403,7 @@ void sqlite3MemJournalOpen(sqlite3_file *pJfd){
 int sqlite3JournalCreate(sqlite3_file *pJfd){
   int rc = SQLITE_OK;
   MemJournal *p = (MemJournal*)pJfd;
-  if( p->pMethod==&MemJournalMethods && (
+  if( pJfd->pMethods==&MemJournalMethods && (
 #ifdef SQLITE_ENABLE_ATOMIC_WRITE
      p->nSpill>0
 #else