diff --git a/manifest b/manifest
index 51e9cbd365..fe0eafb459 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C When\sextracting\svalues\sfrom\sa\srecord\sto\suse\sin\san\sUPDATEd\sversion\sof\sthat\srecord,\sapply\sOP_RealAffinity\sif\srequired.\sFix\sfor\s#3992.\s(CVS\s6945)
-D 2009-07-27T10:05:05
+C Do\snot\ssimulate\sOOM\sconditions\sin\sthe\ssqlite3OsXXX()\scalls\sif\sthe\sunderlying\sfile\sis\san\sin-memory\sjournal\sfile.\s(CVS\s6946)
+D 2009-07-27T11:41:21
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in df9359da7a726ccb67a45db905c5447d5c00c6ef
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -141,7 +141,7 @@ F src/mutex_os2.c 6b5a74f812082a8483c3df05b47bbaac2424b9a0
 F src/mutex_unix.c 2f936339dfef1a4c142db290d575a3509b77315f
 F src/mutex_w32.c cd611ebe0671a05e3d5b4e3f37032a45eb2ce612
 F src/notify.c 0127121816d8a861deb0dfd111b495346bf233db
-F src/os.c c2aa4a7d8bb845222e5c37f56cde377b20c3b087
+F src/os.c 5029ae6c88d1869ad9034008a9531658d53438e4
 F src/os.h fa3f4aa0119ff721a2da4b47ffd74406ac864c05
 F src/os_common.h 8c61457df58f1a4bd5f5adc3e90e01b37bf7afbc
 F src/os_os2.c bed77dc26e3a95ce4a204936b9a1ca6fe612fcc5
@@ -739,7 +739,7 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl 672f81d693a03f80f5ae60bfefacd8a349e76746
-P 886e665f6cf780464b280c286b03c9fb5c1a6b2a
-R 899fdca0f993aff7c16e3dca0f2bd4bf
+P 3616766a6f5c8179cc55444c29ecf29cc69f88ce
+R 15dcf1e2e323ed2f20117bf58e184446
 U danielk1977
-Z 8a5d8493499fa3d337872f4bdb3cfbf7
+Z 83c16bc9609be7e94d58c26429e0fd97
diff --git a/manifest.uuid b/manifest.uuid
index 3d3b7953a6..b1ccc420b6 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-3616766a6f5c8179cc55444c29ecf29cc69f88ce
\ No newline at end of file
+d486811715350f315374cc41f3d808a75d140afb
\ No newline at end of file
diff --git a/src/os.c b/src/os.c
index d879b8a4b3..a2b0325c6a 100644
--- a/src/os.c
+++ b/src/os.c
@@ -13,7 +13,7 @@
 ** This file contains OS interface code that is common to all
 ** architectures.
 **
-** $Id: os.c,v 1.126 2009/03/25 14:24:42 drh Exp $
+** $Id: os.c,v 1.127 2009/07/27 11:41:21 danielk1977 Exp $
 */
 #define _SQLITE_OS_C_ 1
 #include "sqliteInt.h"
@@ -37,13 +37,13 @@
 **
 */
 #if defined(SQLITE_TEST) && (SQLITE_OS_WIN==0)
-  #define DO_OS_MALLOC_TEST if (1) {            \
-    void *pTstAlloc = sqlite3Malloc(10);       \
-    if (!pTstAlloc) return SQLITE_IOERR_NOMEM;  \
-    sqlite3_free(pTstAlloc);                    \
+  #define DO_OS_MALLOC_TEST(x) if (!x || !sqlite3IsMemJournal(x)) {     \
+    void *pTstAlloc = sqlite3Malloc(10);                             \
+    if (!pTstAlloc) return SQLITE_IOERR_NOMEM;                       \
+    sqlite3_free(pTstAlloc);                                         \
   }
 #else
-  #define DO_OS_MALLOC_TEST
+  #define DO_OS_MALLOC_TEST(x)
 #endif
 
 /*
@@ -61,33 +61,33 @@ int sqlite3OsClose(sqlite3_file *pId){
   return rc;
 }
 int sqlite3OsRead(sqlite3_file *id, void *pBuf, int amt, i64 offset){
-  DO_OS_MALLOC_TEST;
+  DO_OS_MALLOC_TEST(id);
   return id->pMethods->xRead(id, pBuf, amt, offset);
 }
 int sqlite3OsWrite(sqlite3_file *id, const void *pBuf, int amt, i64 offset){
-  DO_OS_MALLOC_TEST;
+  DO_OS_MALLOC_TEST(id);
   return id->pMethods->xWrite(id, pBuf, amt, offset);
 }
 int sqlite3OsTruncate(sqlite3_file *id, i64 size){
   return id->pMethods->xTruncate(id, size);
 }
 int sqlite3OsSync(sqlite3_file *id, int flags){
-  DO_OS_MALLOC_TEST;
+  DO_OS_MALLOC_TEST(id);
   return id->pMethods->xSync(id, flags);
 }
 int sqlite3OsFileSize(sqlite3_file *id, i64 *pSize){
-  DO_OS_MALLOC_TEST;
+  DO_OS_MALLOC_TEST(id);
   return id->pMethods->xFileSize(id, pSize);
 }
 int sqlite3OsLock(sqlite3_file *id, int lockType){
-  DO_OS_MALLOC_TEST;
+  DO_OS_MALLOC_TEST(id);
   return id->pMethods->xLock(id, lockType);
 }
 int sqlite3OsUnlock(sqlite3_file *id, int lockType){
   return id->pMethods->xUnlock(id, lockType);
 }
 int sqlite3OsCheckReservedLock(sqlite3_file *id, int *pResOut){
-  DO_OS_MALLOC_TEST;
+  DO_OS_MALLOC_TEST(id);
   return id->pMethods->xCheckReservedLock(id, pResOut);
 }
 int sqlite3OsFileControl(sqlite3_file *id, int op, void *pArg){
@@ -113,7 +113,7 @@ int sqlite3OsOpen(
   int *pFlagsOut
 ){
   int rc;
-  DO_OS_MALLOC_TEST;
+  DO_OS_MALLOC_TEST(0);
   rc = pVfs->xOpen(pVfs, zPath, pFile, flags, pFlagsOut);
   assert( rc==SQLITE_OK || pFile->pMethods==0 );
   return rc;
@@ -127,7 +127,7 @@ int sqlite3OsAccess(
   int flags, 
   int *pResOut
 ){
-  DO_OS_MALLOC_TEST;
+  DO_OS_MALLOC_TEST(0);
   return pVfs->xAccess(pVfs, zPath, flags, pResOut);
 }
 int sqlite3OsFullPathname(