diff --git a/manifest b/manifest
index e09f538fbc..9be78e2ab8 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Assorted\sfixes\sto\sthe\shandling\sof\svarious\smalloc()\sfailures.\s(CVS\s2413)
-D 2005-03-21T03:53:38
+C Add\sfunction\sto\srecover\sfrom\sa\smalloc()\sfailure.\s(CVS\s2414)
+D 2005-03-21T04:04:02
 F Makefile.in 5c00d0037104de2a50ac7647a5f12769795957a3
 F Makefile.linux-gcc 06be33b2a9ad4f005a5f42b22c4a19dab3cbb5c7
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -30,8 +30,8 @@ F sqlite3.pc.in 985b9bf34192a549d7d370e0f0b6b34a4f61369a
 F src/alter.c 8ee27ba2d09f26030c145a780ec8a93cd876d315
 F src/attach.c 3615dbe960cbee4aa5ea300b8a213dad36527b0f
 F src/auth.c 18c5a0befe20f3a58a41e3ddd78f372faeeefe1f
-F src/btree.c 1d9b2179ccac13970c883da6ae3758cc72978bb0
-F src/btree.h 2e2cc923224649337d7217df0dd32b06673ca180
+F src/btree.c c33c0e6833eb8ac0f0941c1f8e722f7c70dbef57
+F src/btree.h 41a71ce027db9ddee72cb43df2316bbe3a1d92af
 F src/build.c 2dc89aa35a0b4aa318ff9eac941f8412fa6db5df
 F src/date.c 2134ef4388256e8247405178df8a61bd60dc180a
 F src/delete.c d70d54a84695de92efc05b9db7d3684cd21d9094
@@ -42,7 +42,7 @@ F src/hash.c 2b1b13f7400e179631c83a1be0c664608c8f021f
 F src/hash.h 1b0c445e1c89ff2aaad9b4605ba61375af001e84
 F src/insert.c 34c25c33f51a43644a42cc091ac967b070c6b6d5
 F src/legacy.c d58ea507bce885298a2c8c3cbb0f4bff5d47830b
-F src/main.c 90cb84bbb85aa89442af41ad4323b136af6527b7
+F src/main.c 2062faded47289c50cdbc083e00d1aa9a872f1a1
 F src/md5.c 7ae1c39044b95de2f62e066f47bb1deb880a1070
 F src/os.h 0c805df3df02b98eb78a7a86756c3cbd4e190939
 F src/os_common.h 0e7f428ba0a6c40a61bc56c4e96f493231301b73
@@ -52,19 +52,19 @@ F src/os_unix.c fba0167576f09e242afd4c4978e1d2944b1da8b5
 F src/os_unix.h 40b2fd1d02cfa45d6c3dea25316fd019cf9fcb0c
 F src/os_win.c 2bbbe6fbb010763c3fa79d5e951afca9b138c6b5
 F src/os_win.h 41a946bea10f61c158ce8645e7646b29d44f122b
-F src/pager.c f12044be70383010510d06668e3b6c94f78a4726
-F src/pager.h 70d496f372163abb6340f474288c4bb9ea962cf7
+F src/pager.c d6ba3096969bc306c46b7db9c11cfe0bbedcc9b9
+F src/pager.h 9a417a1e04737c227ebbba3bdf8597d6dd51513a
 F src/parse.y 10c0ace9efce31d5a06e03488a4284b9d97abc56
 F src/pragma.c 4b20dbc0f4b97f412dc511853d3d0c2e0d4adedc
 F src/printf.c 3d20b21cfecadacecac3fb7274e746cb81d3d357
 F src/random.c eff68e3f257e05e81eae6c4d50a51eb88beb4ff3
 F src/select.c 85695750854188d1eb2d82e0439c99ed6e82645e
 F src/shell.c 25b3217d7c64e6497225439d261a253a23efff26
-F src/sqlite.h.in c85f6bad9ca7de29f505fe886646cfff7df4c55e
-F src/sqliteInt.h 9b2aa887e79b2ecadc24f0b30363b9ec1e5b51e3
+F src/sqlite.h.in 33e7201f78b3f4aa306d885b69e68fa0f0286368
+F src/sqliteInt.h ecb1592406cf4c684f0ad9ce1bc4fe2a37a61efb
 F src/table.c 25b3ff2b39b7d87e8d4a5da0713d68dfc06cbee9
 F src/tclsqlite.c 29e56ecdb94c4066dbe6b088d12cc2404bc9597e
-F src/test1.c dd3e4961f3b9b235a68d4af5d77a06eb7be73184
+F src/test1.c 13d1d2198b3267c8dc6abd22ada4a992c79acefc
 F src/test2.c 7f0ef466706ac01414e1136b96e5d8a65cb97545
 F src/test3.c 683e1e3819152ffd35da2f201e507228921148d0
 F src/test4.c 7c6b9fc33dd1f3f93c7f1ee6e5e6d016afa6c1df
@@ -154,6 +154,7 @@ F test/lock2.test 59c3dd7d9b24d1bf7ec91b2d1541c37e97939d5f
 F test/lock3.test 615111293cf32aa2ed16d01c6611737651c96fb9
 F test/main.test febb69416071134dc38b9b1971c0c2e5b0ca3ff8
 F test/malloc.test b7bc72bb1627e09d6003f58de9bcd6e4be839753
+F test/malloc2.test 5375a1cd53caffd56fd06410c5bddc10f6dccded
 F test/memdb.test 1860e060be810bf0775bc57408a5b7c4954bcaea
 F test/memleak.test df2b2b96e77f8ba159a332299535b1e5f18e49ac
 F test/minmax.test 9429a06f1f93acf76fcacafd17160a4392e88526
@@ -172,7 +173,7 @@ F test/pagesize.test 1b826d1608fd86d2303aa895b5586052ad07eba1
 F test/pragma.test 52e4ba758004e2200ff153d09c8b92f19bf940bc
 F test/printf.test 92ba4c510b4fc61120ffa4a01820446ed917ae57
 F test/progress.test 16496001da445e6534afb94562c286708316d82f x
-F test/quick.test 91e5b8ae6663dc9e3e754b271f0384f0cae706e6
+F test/quick.test 869345bbe45fdad6e3fcc0fc9ec116c0499530c3
 F test/quote.test 6d75cf635d93ba2484dc9cb378d88cbae9dc2c62
 F test/reindex.test 38b138abe36bf9a08c791ed44d9f76cd6b97b78b
 F test/rollback.test 94cd981ee3a627d9f6466f69dcf1f7dbfe695d7a
@@ -277,7 +278,7 @@ F www/tclsqlite.tcl e73f8f8e5f20e8277619433f7970060ab01088fc
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 092a01f5ef430d2c4acc0ae558d74c4bb89638a0
 F www/whentouse.tcl 528299b8316726dbcc5548e9aa0648c8b1bd055b
-P 21012bba176035ff69f860936794a6c2a8eac9df
-R 277a3536d0f906527a71bca818fa2ef9
+P e7844a01c248e8d9204ea9214bec84c81dc07f32
+R f4236514887458fc97a3ba49da042ffa
 U danielk1977
-Z c73e8357d1c9dc50a07df66e791e69aa
+Z 3885f9adee945c24942080cd5fadfb47
diff --git a/manifest.uuid b/manifest.uuid
index 3e9415fd6f..48a178a3e4 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-e7844a01c248e8d9204ea9214bec84c81dc07f32
\ No newline at end of file
+1f9d10d7965c95d1e35f64cf4c3f128adabd41f2
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index a83fe5636c..b2c34e533f 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btree.c,v 1.252 2005/03/14 02:01:50 drh Exp $
+** $Id: btree.c,v 1.253 2005/03/21 04:04:02 danielk1977 Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** For a detailed discussion of BTrees, refer to
@@ -2160,12 +2160,11 @@ int sqlite3BtreeCursor(
     goto create_cursor_exception;
   }
   pCur->pgnoRoot = (Pgno)iTable;
+  pCur->pPage = 0;  /* For exit-handler, in case getAndInitPage() fails. */
   if( iTable==1 && sqlite3pager_pagecount(pBt->pPager)==0 ){
     rc = SQLITE_EMPTY;
-    pCur->pPage = 0;
     goto create_cursor_exception;
   }
-  pCur->pPage = 0;  /* For exit-handler, in case getAndInitPage() fails. */
   rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->pPage, 0);
   if( rc!=SQLITE_OK ){
     goto create_cursor_exception;
@@ -3252,8 +3251,8 @@ static int clearCell(MemPage *pPage, unsigned char *pCell){
     if( rc ) return rc;
     ovflPgno = get4byte(pOvfl->aData);
     rc = freePage(pOvfl);
-    if( rc ) return rc;
     sqlite3pager_unref(pOvfl->aData);
+    if( rc ) return rc;
   }
   return SQLITE_OK;
 }
@@ -3525,7 +3524,8 @@ static int insertCell(
     end = cellOffset + 2*pPage->nCell + 2;
     ins = cellOffset + 2*i;
     if( end > top - sz ){
-      defragmentPage(pPage);
+      int rc = defragmentPage(pPage);
+      if( rc!=SQLITE_OK ) return rc;
       top = get2byte(&data[hdr+5]);
       assert( end + sz <= top );
     }
@@ -4406,7 +4406,7 @@ static int balance_deeper(MemPage *pPage){
   memcpy(&cdata[brk], &data[brk], usableSize-brk);
   assert( pChild->isInit==0 );
   rc = initPage(pChild, pPage);
-  if( rc ) return rc;
+  if( rc ) goto balancedeeper_out;
   memcpy(pChild->aOvfl, pPage->aOvfl, pPage->nOverflow*sizeof(pPage->aOvfl[0]));
   pChild->nOverflow = pPage->nOverflow;
   if( pChild->nOverflow ){
@@ -4420,7 +4420,7 @@ static int balance_deeper(MemPage *pPage){
   if( pBt->autoVacuum ){
     int i;
     rc = ptrmapPut(pBt, pChild->pgno, PTRMAP_BTREE, pPage->pgno);
-    if( rc ) return rc;
+    if( rc ) goto balancedeeper_out;
     for(i=0; i<pChild->nCell; i++){
       rc = ptrmapPutOvfl(pChild, i);
       if( rc!=SQLITE_OK ){
@@ -4430,6 +4430,8 @@ static int balance_deeper(MemPage *pPage){
   }
 #endif
   rc = balance_nonroot(pChild);
+
+balancedeeper_out:
   releasePage(pChild);
   return rc;
 }
@@ -4616,7 +4618,7 @@ int sqlite3BtreeDelete(BtCursor *pCur){
     unsigned char *pNext;
     int szNext;
     int notUsed;
-    unsigned char *tempCell;
+    unsigned char *tempCell = 0;
     assert( !pPage->leafData );
     getTempCursor(pCur, &leafCur);
     rc = sqlite3BtreeNext(&leafCur, &notUsed);
@@ -4624,26 +4626,34 @@ int sqlite3BtreeDelete(BtCursor *pCur){
       if( rc!=SQLITE_NOMEM ){
         rc = SQLITE_CORRUPT;  /* bkpt-CORRUPT */
       }
-      return rc;
     }
-    rc = sqlite3pager_write(leafCur.pPage->aData);
-    if( rc ) return rc;
-    TRACE(("DELETE: table=%d delete internal from %d replace from leaf %d\n",
-       pCur->pgnoRoot, pPage->pgno, leafCur.pPage->pgno));
-    dropCell(pPage, pCur->idx, cellSizePtr(pPage, pCell));
-    pNext = findCell(leafCur.pPage, leafCur.idx);
-    szNext = cellSizePtr(leafCur.pPage, pNext);
-    assert( MX_CELL_SIZE(pBt)>=szNext+4 );
-    tempCell = sqliteMallocRaw( MX_CELL_SIZE(pBt) );
-    if( tempCell==0 ) return SQLITE_NOMEM;
-    rc = insertCell(pPage, pCur->idx, pNext-4, szNext+4, tempCell, 0);
-    if( rc!=SQLITE_OK ) return rc;
-    put4byte(findOverflowCell(pPage, pCur->idx), pgnoChild);
-    rc = balance(pPage, 0);
+    if( rc==SQLITE_OK ){
+      rc = sqlite3pager_write(leafCur.pPage->aData);
+    }
+    if( rc==SQLITE_OK ){
+      TRACE(("DELETE: table=%d delete internal from %d replace from leaf %d\n",
+         pCur->pgnoRoot, pPage->pgno, leafCur.pPage->pgno));
+      dropCell(pPage, pCur->idx, cellSizePtr(pPage, pCell));
+      pNext = findCell(leafCur.pPage, leafCur.idx);
+      szNext = cellSizePtr(leafCur.pPage, pNext);
+      assert( MX_CELL_SIZE(pBt)>=szNext+4 );
+      tempCell = sqliteMallocRaw( MX_CELL_SIZE(pBt) );
+      if( tempCell==0 ){
+        rc = SQLITE_NOMEM;
+      }
+    }
+    if( rc==SQLITE_OK ){
+      rc = insertCell(pPage, pCur->idx, pNext-4, szNext+4, tempCell, 0);
+    }
+    if( rc==SQLITE_OK ){
+      put4byte(findOverflowCell(pPage, pCur->idx), pgnoChild);
+      rc = balance(pPage, 0);
+    }
+    if( rc==SQLITE_OK ){
+      dropCell(leafCur.pPage, leafCur.idx, szNext);
+      rc = balance(leafCur.pPage, 0);
+    }
     sqliteFree(tempCell);
-    if( rc ) return rc;
-    dropCell(leafCur.pPage, leafCur.idx, szNext);
-    rc = balance(leafCur.pPage, 0);
     releaseTempCursor(&leafCur);
   }else{
     TRACE(("DELETE: table=%d delete from leaf %d\n",
@@ -4651,7 +4661,9 @@ int sqlite3BtreeDelete(BtCursor *pCur){
     dropCell(pPage, pCur->idx, cellSizePtr(pPage, pCell));
     rc = balance(pPage, 0);
   }
-  moveToRoot(pCur);
+  if( rc==SQLITE_OK ){
+    moveToRoot(pCur);
+  }
   return rc;
 }
 
@@ -4792,7 +4804,7 @@ static int clearDatabasePage(
   MemPage *pParent,     /* Parent page.  NULL for the root */
   int freePageFlag      /* Deallocate page if true */
 ){
-  MemPage *pPage;
+  MemPage *pPage = 0;
   int rc;
   unsigned char *pCell;
   int i;
@@ -4802,27 +4814,29 @@ static int clearDatabasePage(
   }
 
   rc = getAndInitPage(pBt, pgno, &pPage, pParent);
-  if( rc ) return rc;
+  if( rc ) goto cleardatabasepage_out;
   rc = sqlite3pager_write(pPage->aData);
-  if( rc ) return rc;
+  if( rc ) goto cleardatabasepage_out;
   for(i=0; i<pPage->nCell; i++){
     pCell = findCell(pPage, i);
     if( !pPage->leaf ){
       rc = clearDatabasePage(pBt, get4byte(pCell), pPage->pParent, 1);
-      if( rc ) return rc;
+      if( rc ) goto cleardatabasepage_out;
     }
     rc = clearCell(pPage, pCell);
-    if( rc ) return rc;
+    if( rc ) goto cleardatabasepage_out;
   }
   if( !pPage->leaf ){
     rc = clearDatabasePage(pBt, get4byte(&pPage->aData[8]), pPage->pParent, 1);
-    if( rc ) return rc;
+    if( rc ) goto cleardatabasepage_out;
   }
   if( freePageFlag ){
     rc = freePage(pPage);
   }else{
     zeroPage(pPage, pPage->aData[0] | PTF_LEAF);
   }
+
+cleardatabasepage_out:
   releasePage(pPage);
   return rc;
 }
@@ -4896,7 +4910,10 @@ int sqlite3BtreeDropTable(Btree *pBt, int iTable, int *piMoved){
   rc = getPage(pBt, (Pgno)iTable, &pPage);
   if( rc ) return rc;
   rc = sqlite3BtreeClearTable(pBt, iTable);
-  if( rc ) return rc;
+  if( rc ){
+    releasePage(pPage);
+    return rc;
+  }
 
   *piMoved = 0;
 
@@ -5755,3 +5772,16 @@ int sqlite3BtreeSync(Btree *pBt, const char *zMaster){
   }
   return SQLITE_OK;
 }
+
+#ifndef SQLITE_OMIT_GLOBALRECOVER
+/*
+** Reset the btree and underlying pager after a malloc() failure. Any
+** transaction that was active when malloc() failed is rolled back.
+*/
+int sqlite3BtreeReset(Btree *pBt){
+  if( pBt->pCursor ) return SQLITE_BUSY;
+  pBt->inTrans = TRANS_NONE;
+  unlockBtreeIfUnused(pBt);
+  return sqlite3pager_reset(pBt->pPager);
+}
+#endif
diff --git a/src/btree.h b/src/btree.h
index 7426673537..19bb3d8f8d 100644
--- a/src/btree.h
+++ b/src/btree.h
@@ -13,7 +13,7 @@
 ** subsystem.  See comments in the source code for a detailed description
 ** of what each interface routine does.
 **
-** @(#) $Id: btree.h,v 1.62 2005/02/06 02:45:42 drh Exp $
+** @(#) $Id: btree.h,v 1.63 2005/03/21 04:04:03 danielk1977 Exp $
 */
 #ifndef _BTREE_H_
 #define _BTREE_H_
@@ -73,6 +73,7 @@ int sqlite3BtreeCreateTable(Btree*, int*, int flags);
 int sqlite3BtreeIsInTrans(Btree*);
 int sqlite3BtreeIsInStmt(Btree*);
 int sqlite3BtreeSync(Btree*, const char *zMaster);
+int sqlite3BtreeReset(Btree *);
 
 const char *sqlite3BtreeGetFilename(Btree *);
 const char *sqlite3BtreeGetDirname(Btree *);
diff --git a/src/main.c b/src/main.c
index 8e7ca89a5a..dca52977c4 100644
--- a/src/main.c
+++ b/src/main.c
@@ -14,7 +14,7 @@
 ** other files are for internal use by SQLite and should not be
 ** accessed by users of the library.
 **
-** $Id: main.c,v 1.282 2005/03/09 12:26:51 danielk1977 Exp $
+** $Id: main.c,v 1.283 2005/03/21 04:04:03 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -26,6 +26,16 @@
 */
 const int sqlite3one = 1;
 
+#ifndef SQLITE_OMIT_GLOBALRECOVER
+/*
+** Linked list of all open database handles. This is used by the 
+** sqlite3_global_recover() function. Entries are added to the list
+** by openDatabase() and removed by sqlite3_close().
+*/
+static sqlite3 *pDbList = 0;
+#endif
+
+
 /*
 ** Fill the InitData structure with an error message that indicates
 ** that the database is corrupt.
@@ -514,6 +524,23 @@ int sqlite3_close(sqlite3 *db){
     sqlite3ValueFree(db->pErr);
   }
 
+#ifndef SQLITE_OMIT_GLOBALRECOVER
+  {
+    sqlite3 *pPrev = pDbList;
+    sqlite3OsEnterMutex();
+    while( pPrev && pPrev->pNext!=db ){
+      pPrev = pPrev->pNext;
+    }
+    if( pPrev ){
+      pPrev->pNext = db->pNext;
+    }else{
+      assert( pDbList==db );
+      pDbList = db->pNext;
+    }
+    sqlite3OsLeaveMutex();
+  }
+#endif
+
   db->magic = SQLITE_MAGIC_ERROR;
   sqliteFree(db);
   return SQLITE_OK;
@@ -1199,6 +1226,14 @@ opendb_out:
     sqlite3Error(db, SQLITE_NOMEM, 0);
   }
   *ppDb = db;
+#ifndef SQLITE_OMIT_GLOBALRECOVER
+  if( db ){
+    sqlite3OsEnterMutex();
+    db->pNext = pDbList;
+    pDbList = db;
+    sqlite3OsLeaveMutex();
+  }
+#endif
   return sqlite3_errcode(db);
 }
 
@@ -1400,3 +1435,39 @@ int sqlite3_collation_needed16(
   return SQLITE_OK;
 }
 #endif /* SQLITE_OMIT_UTF16 */
+
+#ifndef SQLITE_OMIT_GLOBALRECOVER
+/*
+** This function is called to recover from a malloc failure that occured
+** within SQLite. 
+**
+** This function is *not* threadsafe. Calling this from within a threaded
+** application when threads other than the caller have used SQLite is 
+** dangerous and will almost certainly result in malfunctions.
+*/
+int sqlite3_global_recover(){
+  int rc = SQLITE_OK;
+
+  if( sqlite3_malloc_failed ){
+    sqlite3 *db;
+    int i;
+    sqlite3_malloc_failed = 0;
+    for(db=pDbList; db; db=db->pNext ){
+      sqlite3ExpirePreparedStatements(db);
+      for(i=0; i<db->nDb; i++){
+        Btree *pBt = db->aDb[i].pBt;
+        if( pBt && (rc=sqlite3BtreeReset(pBt)) ){
+          goto recover_out;
+        }
+      } 
+      db->autoCommit = 1;
+    }
+  }
+
+recover_out:
+  if( rc!=SQLITE_OK ){
+    sqlite3_malloc_failed = 1;
+  }
+  return rc;
+}
+#endif
diff --git a/src/pager.c b/src/pager.c
index cfe0301713..9c6040a628 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.197 2005/03/21 03:53:38 danielk1977 Exp $
+** @(#) $Id: pager.c,v 1.198 2005/03/21 04:04:02 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -844,6 +844,28 @@ static void pager_reset(Pager *pPager){
   assert( pPager->journalOpen==0 );
 }
 
+/*
+** This function is used to reset the pager after a malloc() failure. This
+** doesn't work with in-memory databases. If a malloc() fails when an 
+** in-memory database is in use it is not possible to recover.
+**
+** If a transaction or statement transaction is active, it is rolled back.
+**
+** It is an error to call this function if any pages are in use.
+*/
+#ifndef SQLITE_OMIT_GLOBALRECOVER
+int sqlite3pager_reset(Pager *pPager){
+  if( pPager ){
+    if( pPager->nRef || MEMDB ){
+      return SQLITE_ERROR;
+    }
+    pPager->errMask &= ~(PAGER_ERR_MEM);
+    pager_reset(pPager);
+  }
+  return SQLITE_OK;
+}
+#endif
+
 
 /*
 ** When this routine is called, the pager has the journal file open and
diff --git a/src/pager.h b/src/pager.h
index 8e88c86eb2..442df76a45 100644
--- a/src/pager.h
+++ b/src/pager.h
@@ -13,7 +13,7 @@
 ** subsystem.  The page cache subsystem reads and writes a file a page
 ** at a time and provides a journal for rollback.
 **
-** @(#) $Id: pager.h,v 1.41 2005/02/06 02:45:42 drh Exp $
+** @(#) $Id: pager.h,v 1.42 2005/03/21 04:04:03 danielk1977 Exp $
 */
 
 /*
@@ -100,6 +100,7 @@ const char *sqlite3pager_journalname(Pager*);
 int sqlite3pager_rename(Pager*, const char *zNewName);
 void sqlite3pager_set_codec(Pager*,void(*)(void*,void*,Pgno,int),void*);
 int sqlite3pager_movepage(Pager*,void*,Pgno);
+int sqlite3pager_reset(Pager*);
 
 #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
 int sqlite3pager_lockstate(Pager*);
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index 430bd2cf11..613b98b7d8 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -12,7 +12,7 @@
 ** This header file defines the interface that the SQLite library
 ** presents to client programs.
 **
-** @(#) $Id: sqlite.h.in,v 1.130 2005/02/05 07:33:35 danielk1977 Exp $
+** @(#) $Id: sqlite.h.in,v 1.131 2005/03/21 04:04:03 danielk1977 Exp $
 */
 #ifndef _SQLITE3_H_
 #define _SQLITE3_H_
@@ -1215,11 +1215,32 @@ int sqlite3_expired(sqlite3_stmt*);
 ** is NULL pointer, then SQLite does a search for an appropriate temporary
 ** file directory.
 **
-** Once sqlite3_open() has been called, changing this variable will invalidate the
-** current temporary database, if any.
+** Once sqlite3_open() has been called, changing this variable will invalidate
+** the current temporary database, if any.
 */
 extern char *sqlite3_temp_directory;
 
+/*
+** This function is called to recover from a malloc() failure that occured
+** within the SQLite library. Normally, after a single malloc() fails the 
+** library refuses to function (all major calls return SQLITE_NOMEM).
+** This function library state so that it can be used again.
+**
+** All existing statements (sqlite3_stmt pointers) must be finalized or
+** reset before this call is made. Otherwise, SQLITE_BUSY is returned.
+** If any in-memory databases are in use, either as a main or TEMP
+** database, SQLITE_ERROR is returned. In either of these cases, the 
+** library is not reset and remains unusable.
+**
+** This function is *not* threadsafe. Calling this from within a threaded
+** application when threads other than the caller have used SQLite is
+** dangerous and will almost certainly result in malfunctions.
+**
+** This functionality can be omitted from a build by defining the 
+** SQLITE_OMIT_GLOBALRECOVER at compile time.
+*/
+int sqlite3_global_recover();
+
 #ifdef __cplusplus
 }  /* End of the 'extern "C"' block */
 #endif
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index f5e79a9510..3934a6b631 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -11,7 +11,7 @@
 *************************************************************************
 ** Internal interface definitions for SQLite.
 **
-** @(#) $Id: sqliteInt.h,v 1.373 2005/03/17 05:03:40 danielk1977 Exp $
+** @(#) $Id: sqliteInt.h,v 1.374 2005/03/21 04:04:03 danielk1977 Exp $
 */
 #ifndef _SQLITEINT_H_
 #define _SQLITEINT_H_
@@ -452,6 +452,9 @@ struct sqlite3 {
   sqlite3_value *pErr;          /* Most recent error message */
   char *zErrMsg;                /* Most recent error message (UTF-8 encoded) */
   char *zErrMsg16;              /* Most recent error message (UTF-16 encoded) */
+#ifndef SQLITE_OMIT_GLOBALRECOVER
+  sqlite3 *pNext;               /* Linked list of open db handles. */
+#endif
 };
 
 /*
diff --git a/src/test1.c b/src/test1.c
index 52e75217d5..62855f695d 100644
--- a/src/test1.c
+++ b/src/test1.c
@@ -13,7 +13,7 @@
 ** is not included in the SQLite library.  It is used for automated
 ** testing of the SQLite library.
 **
-** $Id: test1.c,v 1.134 2005/03/11 04:41:40 drh Exp $
+** $Id: test1.c,v 1.135 2005/03/21 04:04:02 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include "tcl.h"
@@ -2294,6 +2294,24 @@ static int test_stmt_utf8(
   return TCL_OK;
 }
 
+static int test_global_recover(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#ifndef SQLITE_OMIT_GLOBALRECOVER
+  int rc;
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }
+  rc = sqlite3_global_recover();
+  Tcl_SetResult(interp, (char *)errorName(rc), TCL_STATIC);
+#endif
+  return TCL_OK;
+}
+
 /*
 ** Usage: sqlite3_column_text STMT column
 **
@@ -2765,6 +2783,12 @@ static void set_options(Tcl_Interp *interp){
   Tcl_SetVar2(interp, "sqlite_options", "foreignkey", "1", TCL_GLOBAL_ONLY);
 #endif
 
+#ifdef SQLITE_OMIT_GLOBALRECOVER
+  Tcl_SetVar2(interp, "sqlite_options", "globalrecover", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "globalrecover", "1", TCL_GLOBAL_ONLY);
+#endif
+
 #ifdef SQLITE_OMIT_INTEGRITY_CHECK
   Tcl_SetVar2(interp, "sqlite_options", "integrityck", "0", TCL_GLOBAL_ONLY);
 #else
@@ -2952,6 +2976,7 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
      { "sqlite3_column_decltype16", test_stmt_utf16, sqlite3_column_decltype16},
      { "sqlite3_column_name16",     test_stmt_utf16, sqlite3_column_name16    },
 #endif
+     { "sqlite3_global_recover",    test_global_recover, 0   },
 
      /* Functions from os.h */
      { "sqlite3OsOpenReadWrite",test_sqlite3OsOpenReadWrite, 0 },
diff --git a/test/malloc2.test b/test/malloc2.test
new file mode 100644
index 0000000000..15e41bfa5f
--- /dev/null
+++ b/test/malloc2.test
@@ -0,0 +1,335 @@
+# 2005 March 18
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file attempts to check that the library can recover from a malloc()
+# failure when sqlite3_global_recover() is invoked.
+#
+# $Id: malloc2.test,v 1.1 2005/03/21 04:04:03 danielk1977 Exp $
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+# Only run these tests if memory debugging is turned on.
+#
+if {[info command sqlite_malloc_stat]==""} {
+  puts "Skipping malloc tests: not compiled with -DSQLITE_DEBUG..."
+  finish_test
+  return
+}
+
+ifcapable !globalrecover {
+  finish_test
+  return
+}
+
+# Generate a checksum based on the contents of the database. If the
+# checksum of two databases is the same, and the integrity-check passes
+# for both, the two databases are identical.
+#
+proc cksum {db} {
+  set ret [list]
+  set sql {
+    SELECT name FROM sqlite_master WHERE type = 'table' UNION
+    SELECT name FROM sqlite_temp_master WHERE type = 'table' UNION
+    SELECT 'sqlite_master' UNION
+    SELECT 'sqlite_temp_master'
+  }
+  foreach tbl [$db eval $sql] {
+    set cols [list]
+    $db eval "PRAGMA table_info($tbl)" {
+      lappend cols $name
+    }
+    set sql "SELECT md5sum([join $cols ,]) FROM $tbl"
+    lappend ret [db onecolumn $sql]
+  }
+  return $ret
+}
+
+proc do_malloc2_test {tn args} {
+  array set ::mallocopts $args
+  set sum [cksum db]
+
+  for {set ::n 1} {true} {incr ::n} {
+
+    # Run the SQL. Malloc number $::n is set to fail. A malloc() failure
+    # may or may not be reported.
+    sqlite_malloc_fail $::n
+    do_test malloc2-$tn.$::n.2 {
+      set res [catchsql $::mallocopts(-sql)]
+      set rc [expr { 
+        0==[string compare $res {1 {out of memory}}] ||
+        0==[lindex $res 0]
+      }]
+      if {$rc!=1} {
+        puts "Error: $res"
+      }
+      set rc
+    } {1}
+
+    # If $::n is greater than the number of malloc() calls required to
+    # execute the SQL, then this test is finished. Break out of the loop.
+    if {[lindex [sqlite_malloc_stat] 2]>0} {
+      sqlite_malloc_fail -1
+      break
+    }
+
+    # Nothing should work now, because the allocator should refuse to
+    # allocate any memory.
+    do_test malloc2-$tn.$::n.3 {
+      catchsql {SELECT 'nothing should work'}
+    } {1 {out of memory}}
+
+    # Recover from the malloc failure.
+    do_test malloc2-$tn.$::n.4 {
+      if 0 {
+        db close
+        sqlite_malloc_fail -1
+        set ::DB [sqlite3 db test.db]
+        set dummy SQLITE_OK
+      } else {
+        sqlite3_global_recover
+      }
+    } {SQLITE_OK}
+
+    # Checksum the database.
+    do_test malloc2-$tn.$::n.5 {
+      cksum db
+    } $sum
+
+    integrity_check malloc2-$tn.$::n.6
+  if {$::nErr>1} return
+  }
+  unset ::mallocopts
+}
+
+do_test malloc2.1.setup {
+  execsql {
+    CREATE TABLE abc(a, b, c);
+    INSERT INTO abc VALUES(10, 20, 30);
+    INSERT INTO abc VALUES(40, 50, 60);
+    CREATE INDEX abc_i ON abc(a, b, c);
+  }
+} {}
+do_malloc2_test 1.1 -sql {
+  SELECT * FROM abc;
+}
+do_malloc2_test 1.2 -sql {
+  UPDATE abc SET c = c+10;
+}
+do_malloc2_test 1.3 -sql {
+  INSERT INTO abc VALUES(70, 80, 90);
+}
+do_malloc2_test 1.4 -sql {
+  DELETE FROM abc;
+}
+do_test malloc2.1.5 {
+  execsql {
+    SELECT * FROM abc;
+  }
+} {}
+
+do_test malloc2.2.setup {
+  execsql {
+    CREATE TABLE def(a, b, c);
+    CREATE INDEX def_i1 ON def(a);
+    CREATE INDEX def_i2 ON def(c);
+    BEGIN;
+  }
+  for {set i 0} {$i<20} {incr i} {
+    execsql {
+    INSERT INTO def VALUES(randstr(300,300),randstr(300,300),randstr(300,300));
+    }
+  }
+  execsql {
+    COMMIT;
+  }
+} {}
+do_malloc2_test 2 -sql {
+  BEGIN;
+  UPDATE def SET a = randstr(100,100) WHERE (oid%9)==0;
+  INSERT INTO def SELECT * FROM def WHERE (oid%13)==0;
+
+  CREATE INDEX def_i3 ON def(b);
+
+  UPDATE def SET a = randstr(100,100) WHERE (oid%9)==1;
+  INSERT INTO def SELECT * FROM def WHERE (oid%13)==1;
+
+  CREATE TABLE def2 AS SELECT * FROM def;
+  DROP TABLE def;
+  CREATE TABLE def AS SELECT * FROM def2;
+  DROP TABLE def2;
+
+  DELETE FROM def WHERE (oid%9)==2;
+  INSERT INTO def SELECT * FROM def WHERE (oid%13)==2;
+  COMMIT;
+}
+
+do_test malloc2.3.setup {
+  execsql {
+    CREATE TEMP TABLE ghi(a, b, c);
+    BEGIN;
+  }
+  for {set i 0} {$i<20} {incr i} {
+    execsql {
+    INSERT INTO ghi VALUES(randstr(300,300),randstr(300,300),randstr(300,300));
+    }
+  }
+  execsql {
+    COMMIT;
+  }
+} {}
+do_malloc2_test 3 -sql {
+  BEGIN;
+  CREATE INDEX ghi_i1 ON ghi(a);
+  UPDATE def SET a = randstr(100,100) WHERE (oid%2)==0;
+  UPDATE ghi SET a = randstr(100,100) WHERE (oid%2)==0;
+  COMMIT;
+}
+
+############################################################################
+# The test cases below are to increase the code coverage in btree.c and 
+# pager.c of this test file. The idea is that each malloc() that occurs in
+# these two source files should be made to fail at least once.
+#
+catchsql {
+  DROP TABLE ghi;
+}
+do_malloc2_test 4.1 -sql {
+  SELECT * FROM def ORDER BY oid ASC;
+  SELECT * FROM def ORDER BY oid DESC;
+}
+do_malloc2_test 4.2 -sql {
+  PRAGMA cache_size = 10;
+  BEGIN;
+
+  -- This will put about 25 pages on the free list.
+  DELETE FROM def WHERE 1;
+
+  -- Allocate 32 new root pages. This will exercise the 'extract specific 
+  -- page from the freelist' code when in auto-vacuum mode (see the
+  -- allocatePage() routine in btree.c).
+  CREATE TABLE t1(a UNIQUE, b UNIQUE, c UNIQUE);
+  CREATE TABLE t2(a UNIQUE, b UNIQUE, c UNIQUE);
+  CREATE TABLE t3(a UNIQUE, b UNIQUE, c UNIQUE);
+  CREATE TABLE t4(a UNIQUE, b UNIQUE, c UNIQUE);
+  CREATE TABLE t5(a UNIQUE, b UNIQUE, c UNIQUE);
+  CREATE TABLE t6(a UNIQUE, b UNIQUE, c UNIQUE);
+  CREATE TABLE t7(a UNIQUE, b UNIQUE, c UNIQUE);
+  CREATE TABLE t8(a UNIQUE, b UNIQUE, c UNIQUE);
+
+  ROLLBACK;
+}
+
+########################################################################
+# Test that the global linked list of database handles works. An assert()
+# will fail if there is some problem.
+do_test malloc2-5 {
+  sqlite3 db1 test.db
+  sqlite3 db2 test.db
+  sqlite3 db3 test.db
+  sqlite3 db4 test.db
+  sqlite3 db5 test.db
+
+  # Close the head of the list:
+  db5 close
+  
+  # Close the end of the list:
+  db1 close
+
+  # Close a handle from the middle of the list:
+  db3 close
+
+  # Close the other two. Then open and close one more database, to make
+  # sure the head of the list was set back to NULL.
+  db2 close
+  db4 close
+  sqlite db1 test.db
+  db1 close
+} {}
+
+########################################################################
+# Check that if a statement is active sqlite3_global_recover doesn't reset
+# the sqlite3_malloc_failed variable.
+do_test malloc2-6.1 {
+  set ::STMT [sqlite3_prepare $::DB {SELECT * FROM def} -1 DUMMY]
+  sqlite3_step $::STMT
+} {SQLITE_ROW}
+do_test malloc2-6.2 {
+  sqlite3 db1 test.db
+  sqlite_malloc_fail 100
+  catchsql {
+    SELECT * FROM def;
+  } db1
+} {1 {out of memory}}
+do_test malloc2-6.3 {
+  sqlite3_global_recover
+} {SQLITE_BUSY}
+do_test malloc2-6.4 {
+  catchsql {
+    SELECT 'hello';
+  }
+} {1 {out of memory}}
+do_test malloc2-6.5 {
+  sqlite3_reset $::STMT
+} {SQLITE_OK}
+do_test malloc2-6.6 {
+  sqlite3_global_recover
+} {SQLITE_OK}
+do_test malloc2-6.7 {
+  catchsql {
+    SELECT 'hello';
+  }
+} {0 hello}
+do_test malloc2-6.8 {
+  sqlite3_step $::STMT
+} {SQLITE_ERROR}
+do_test malloc2-6.9 {
+  sqlite3_finalize $::STMT
+} {SQLITE_SCHEMA}
+do_test malloc2-6.10 {
+  db1 close
+} {}
+
+########################################################################
+# Check that if an in-memory database is being used it is not possible
+# to recover from a malloc() failure.
+ifcapable memorydb {
+  do_test malloc2-7.1 {
+    sqlite3 db1 :memory:
+    list
+  } {}
+  do_test malloc2-7.2 {
+    sqlite_malloc_fail 100
+    catchsql {
+      SELECT * FROM def;
+    } 
+  } {1 {out of memory}}
+  do_test malloc2-7.3 {
+    sqlite3_global_recover
+  } {SQLITE_ERROR}
+  do_test malloc2-7.4 {
+    catchsql {
+      SELECT 'hello';
+    }
+  } {1 {out of memory}}
+  do_test malloc2-7.5 {
+    db1 close
+  } {}
+  do_test malloc2-7.6 {
+    sqlite3_global_recover
+  } {SQLITE_OK}
+  do_test malloc2-7.7 {
+    catchsql {
+      SELECT 'hello';
+    }
+  } {0 hello}
+}
+
+finish_test
diff --git a/test/quick.test b/test/quick.test
index 8cc30cfea0..228a12e862 100644
--- a/test/quick.test
+++ b/test/quick.test
@@ -10,7 +10,7 @@
 #***********************************************************************
 # This file runs all tests.
 #
-# $Id: quick.test,v 1.33 2004/11/13 13:19:56 danielk1977 Exp $
+# $Id: quick.test,v 1.34 2005/03/21 04:04:03 danielk1977 Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -28,6 +28,7 @@ set EXCLUDE {
   corrupt.test
   crash.test
   malloc.test
+  malloc2.test
   memleak.test
   misuse.test
   quick.test