Index: src/pcache.c
==================================================================
--- src/pcache.c
+++ src/pcache.c
@@ -64,56 +64,37 @@
 */
 #if defined(SQLITE_DEBUG) && 0
   int sqlite3PcacheTrace = 2;       /* 0: off  1: simple  2: cache dumps */
   int sqlite3PcacheMxDump = 9999;   /* Max cache entries for pcacheDump() */
 # define pcacheTrace(X) if(sqlite3PcacheTrace){sqlite3DebugPrintf X;}
-  static void pcachePageTrace(int i, sqlite3_pcache_page *pLower){
+  void pcacheDump(PCache *pCache){
+    int N;
+    int i, j;
+    sqlite3_pcache_page *pLower;
     PgHdr *pPg;
     unsigned char *a;
-    int j;
-    pPg = (PgHdr*)pLower->pExtra;
-    printf("%3d: nRef %2d flgs %02x data ", i, pPg->nRef, pPg->flags);
-    a = (unsigned char *)pLower->pBuf;
-    for(j=0; j<12; j++) printf("%02x", a[j]);
-    printf(" ptr %p\n", pPg);
-  }
-  static void pcacheDump(PCache *pCache){
-    int N;
-    int i;
-    sqlite3_pcache_page *pLower;
   
     if( sqlite3PcacheTrace<2 ) return;
     if( pCache->pCache==0 ) return;
     N = sqlite3PcachePagecount(pCache);
     if( N>sqlite3PcacheMxDump ) N = sqlite3PcacheMxDump;
     for(i=1; i<=N; i++){
        pLower = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, i, 0);
        if( pLower==0 ) continue;
-       pcachePageTrace(i, pLower);
-       if( ((PgHdr*)pLower)->pPage==0 ){
+       pPg = (PgHdr*)pLower->pExtra;
+       printf("%3d: nRef %2d flgs %02x data ", i, pPg->nRef, pPg->flags);
+       a = (unsigned char *)pLower->pBuf;
+       for(j=0; j<12; j++) printf("%02x", a[j]);
+       printf("\n");
+       if( pPg->pPage==0 ){
          sqlite3GlobalConfig.pcache2.xUnpin(pCache->pCache, pLower, 0);
        }
     }
   }
-#else
+  #else
 # define pcacheTrace(X)
-# define pcachePageTrace(PGNO, X)
 # define pcacheDump(X)
-#endif
-
-/*
-** Return 1 if pPg is on the dirty list for pCache.  Return 0 if not.
-** This routine runs inside of assert() statements only.
-*/
-#ifdef SQLITE_DEBUG
-static int pageOnDirtyList(PCache *pCache, PgHdr *pPg){
-  PgHdr *p;
-  for(p=pCache->pDirty; p; p=p->pDirtyNext){
-    if( p==pPg ) return 1;
-  }
-  return 0;
-}
 #endif
 
 /*
 ** Check invariants on a PgHdr entry.  Return true if everything is OK.
 ** Return false if any invariant is violated.
@@ -130,17 +111,12 @@
   assert( pPg->pgno>0 || pPg->pPager==0 );    /* Page number is 1 or more */
   pCache = pPg->pCache;
   assert( pCache!=0 );      /* Every page has an associated PCache */
   if( pPg->flags & PGHDR_CLEAN ){
     assert( (pPg->flags & PGHDR_DIRTY)==0 );/* Cannot be both CLEAN and DIRTY */
-    assert( !pageOnDirtyList(pCache, pPg) );/* CLEAN pages not on dirty list */
-  }else{
-    assert( (pPg->flags & PGHDR_DIRTY)!=0 );/* If not CLEAN must be DIRTY */
-    assert( pPg->pDirtyNext==0 || pPg->pDirtyNext->pDirtyPrev==pPg );
-    assert( pPg->pDirtyPrev==0 || pPg->pDirtyPrev->pDirtyNext==pPg );
-    assert( pPg->pDirtyPrev!=0 || pCache->pDirty==pPg );
-    assert( pageOnDirtyList(pCache, pPg) );
+    assert( pCache->pDirty!=pPg );          /* CLEAN pages not on dirty list */
+    assert( pCache->pDirtyTail!=pPg );
   }
   /* WRITEABLE pages must also be DIRTY */
   if( pPg->flags & PGHDR_WRITEABLE ){
     assert( pPg->flags & PGHDR_DIRTY );     /* WRITEABLE implies DIRTY */
   }
@@ -410,13 +386,12 @@
   eCreate = createFlag & pCache->eCreate;
   assert( eCreate==0 || eCreate==1 || eCreate==2 );
   assert( createFlag==0 || pCache->eCreate==eCreate );
   assert( createFlag==0 || eCreate==1+(!pCache->bPurgeable||!pCache->pDirty) );
   pRes = sqlite3GlobalConfig.pcache2.xFetch(pCache->pCache, pgno, eCreate);
-  pcacheTrace(("%p.FETCH %d%s (result: %p) ",pCache,pgno,
+  pcacheTrace(("%p.FETCH %d%s (result: %p)\n",pCache,pgno,
                createFlag?" create":"",pRes));
-  pcachePageTrace(pgno, pRes);
   return pRes;
 }
 
 /*
 ** If the sqlite3PcacheFetch() routine is unable to allocate a new
@@ -540,11 +515,10 @@
   if( (--p->nRef)==0 ){
     if( p->flags&PGHDR_CLEAN ){
       pcacheUnpin(p);
     }else{
       pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT);
-      assert( sqlite3PcachePageSanity(p) );
     }
   }
 }
 
 /*
@@ -584,11 +558,10 @@
     if( p->flags & PGHDR_CLEAN ){
       p->flags ^= (PGHDR_DIRTY|PGHDR_CLEAN);
       pcacheTrace(("%p.DIRTY %d\n",p->pCache,p->pgno));
       assert( (p->flags & (PGHDR_DIRTY|PGHDR_CLEAN))==PGHDR_DIRTY );
       pcacheManageDirtyList(p, PCACHE_DIRTYLIST_ADD);
-      assert( sqlite3PcachePageSanity(p) );
     }
     assert( sqlite3PcachePageSanity(p) );
   }
 }
 
@@ -655,11 +628,10 @@
   pcacheTrace(("%p.MOVE %d -> %d\n",pCache,p->pgno,newPgno));
   sqlite3GlobalConfig.pcache2.xRekey(pCache->pCache, p->pPage, p->pgno,newPgno);
   p->pgno = newPgno;
   if( (p->flags&PGHDR_DIRTY) && (p->flags&PGHDR_NEED_SYNC) ){
     pcacheManageDirtyList(p, PCACHE_DIRTYLIST_FRONT);
-    assert( sqlite3PcachePageSanity(p) );
   }
 }
 
 /*
 ** Drop every cache entry whose page number is greater than "pgno". The
@@ -677,11 +649,11 @@
     pcacheTrace(("%p.TRUNCATE %d\n",pCache,pgno));
     for(p=pCache->pDirty; p; p=pNext){
       pNext = p->pDirtyNext;
       /* This routine never gets call with a positive pgno except right
       ** after sqlite3PcacheCleanAll().  So if there are dirty pages,
-      ** it must be that pgno==0.
+      ** it must be that pgno>0.
       */
       assert( p->pgno>0 );
       if( p->pgno>pgno ){
         assert( p->flags&PGHDR_DIRTY );
         sqlite3PcacheMakeClean(p);