diff --git a/mozilla/xpinstall/public/nsPIXPIStubHook.idl b/mozilla/xpinstall/public/nsPIXPIStubHook.idl
index 62e21bcf906..da413623683 100644
--- a/mozilla/xpinstall/public/nsPIXPIStubHook.idl
+++ b/mozilla/xpinstall/public/nsPIXPIStubHook.idl
@@ -35,5 +35,5 @@
 [uuid(089929F0-4ED9-11d3-ABDD-000064657374)]
 interface nsPIXPIStubHook : nsISupports
 {
-        void    StubInitialize(in nsIFile dir);
+        void    StubInitialize(in nsIFile dir, in string logName);
 };
diff --git a/mozilla/xpinstall/src/nsLoggingProgressNotifier.cpp b/mozilla/xpinstall/src/nsLoggingProgressNotifier.cpp
index 9073f7387d8..72712b94be8 100644
--- a/mozilla/xpinstall/src/nsLoggingProgressNotifier.cpp
+++ b/mozilla/xpinstall/src/nsLoggingProgressNotifier.cpp
@@ -80,11 +80,18 @@ nsLoggingProgressListener::BeforeJavascriptEvaluation(const PRUnichar *URL)
 
     if (NS_FAILED(rv)) return rv;
 
+    if (!nsSoftwareUpdate::GetLogName())
+    {
 #ifdef XP_MAC
-    rv = iFile->Append("Install Log");
+        rv = iFile->Append("Install Log");
 #else
-    rv = iFile->Append("install.log");
+        rv = iFile->Append("install.log");
 #endif
+    }
+    else
+        rv = iFile->Append(nsSoftwareUpdate::GetLogName());
+
+    if (NS_FAILED(rv)) return rv;
 
     // create log file if it doesn't exist (to work around a mac filespec bug)
     PRBool bExists = PR_FALSE;
diff --git a/mozilla/xpinstall/src/nsSoftwareUpdate.cpp b/mozilla/xpinstall/src/nsSoftwareUpdate.cpp
index 05389a3f3ca..e8183167762 100644
--- a/mozilla/xpinstall/src/nsSoftwareUpdate.cpp
+++ b/mozilla/xpinstall/src/nsSoftwareUpdate.cpp
@@ -99,6 +99,7 @@ static NS_DEFINE_CID(knsRegistryCID, NS_REGISTRY_CID);
 
 nsSoftwareUpdate* nsSoftwareUpdate::mInstance = nsnull;
 nsCOMPtr<nsIFile> nsSoftwareUpdate::mProgramDir = nsnull;
+char*             nsSoftwareUpdate::mLogName = nsnull;
 
 #if NOTIFICATION_ENABLE
 #include "nsUpdateNotification.h"
@@ -182,6 +183,8 @@ nsSoftwareUpdate::~nsSoftwareUpdate()
     //NS_IF_RELEASE( mProgramDir );
     NS_IF_RELEASE (mMasterListener);
     mInstance = nsnull;
+
+    PR_FREEIF(mLogName);
 }
 
 
@@ -533,13 +536,16 @@ nsSoftwareUpdate::RegisterNameset()
 
 
 NS_IMETHODIMP
-nsSoftwareUpdate::StubInitialize(nsIFile *aDir)
+nsSoftwareUpdate::StubInitialize(nsIFile *aDir, const char* logName)
 {
     if (mStubLockout)
         return NS_ERROR_ABORT;
     else if ( !aDir )
         return NS_ERROR_NULL_POINTER;
 
+    if (logName)
+        PL_strcpy(mLogName, logName);
+
     // only allow once, it could be a mess if we've already started installing
     mStubLockout = PR_TRUE;
 
diff --git a/mozilla/xpinstall/src/nsSoftwareUpdate.h b/mozilla/xpinstall/src/nsSoftwareUpdate.h
index df2d5df559d..cf69d63590d 100644
--- a/mozilla/xpinstall/src/nsSoftwareUpdate.h
+++ b/mozilla/xpinstall/src/nsSoftwareUpdate.h
@@ -42,11 +42,16 @@ class nsSoftwareUpdate: public nsIAppShellComponent,
         static nsSoftwareUpdate *GetInstance();
 
         /** GetProgramDirectory
-         *  information used within the XPI module -- not
+         *  Information used within the XPI module -- not
          *  available through any interface
          */
         static nsIFile* GetProgramDirectory() { return mProgramDir; }
 
+        /** GetLogName
+         *  Optional log name used privately in the XPI module.
+         */
+        static char*    GetLogName() { return mLogName; }
+
         NS_DECL_ISUPPORTS
         NS_DECL_NSIAPPSHELLCOMPONENT
         
@@ -75,7 +80,7 @@ class nsSoftwareUpdate: public nsIAppShellComponent,
          *  once, and is also set by the AppShellComponent initialize
          *  so it can't be called during a normal Mozilla run
          */
-        NS_IMETHOD StubInitialize(nsIFile *dir);
+        NS_IMETHOD StubInitialize(nsIFile *dir, const char* logName);
 
         nsSoftwareUpdate();
         virtual ~nsSoftwareUpdate();
@@ -84,6 +89,7 @@ class nsSoftwareUpdate: public nsIAppShellComponent,
     private:
         static   nsSoftwareUpdate*  mInstance;
         static   nsCOMPtr<nsIFile>  mProgramDir;
+        static   char*              mLogName;
 
 #if NOTIFICATION_ENABLE
         static   nsIUpdateNotification *mUpdateNotifier;
diff --git a/mozilla/xpinstall/stub/xpistub.cpp b/mozilla/xpinstall/stub/xpistub.cpp
index ae664531fbf..c1dc181c93c 100644
--- a/mozilla/xpinstall/stub/xpistub.cpp
+++ b/mozilla/xpinstall/stub/xpistub.cpp
@@ -91,6 +91,7 @@ PR_PUBLIC_API(nsresult) XPI_Init(
 #else
                                     const char*         aProgramDir,
 #endif
+                                    const char*         aLogName,
                                     pfnXPIProgress      progressCB )
 {
     nsresult              rv;
@@ -199,7 +200,7 @@ PR_PUBLIC_API(nsresult) XPI_Init(
 #endif    
     
     if (hook && iDirSpec)
-        hook->StubInitialize( iDirSpec );
+        hook->StubInitialize( iDirSpec, aLogName );
     else
         return NS_ERROR_NULL_POINTER;
 
diff --git a/mozilla/xpinstall/wizard/mac/src/XPInstallGlue.c b/mozilla/xpinstall/wizard/mac/src/XPInstallGlue.c
index a73456e95e8..992a718068d 100644
--- a/mozilla/xpinstall/wizard/mac/src/XPInstallGlue.c
+++ b/mozilla/xpinstall/wizard/mac/src/XPInstallGlue.c
@@ -30,7 +30,7 @@
  *-----------------------------------------------------------*/
 
 /*================== XPI Stub Entry Points ================== */
-typedef		nsresult (*XPI_InitProc)(const FSSpec& aXPIStubDir, const FSSpec& aProgramDir, pfnXPIProgress progressCB);
+typedef		nsresult (*XPI_InitProc)(const FSSpec& aXPIStubDir, const FSSpec& aProgramDir, const char* aLogName, pfnXPIProgress progressCB);
 typedef 	nsresult (*XPI_InstallProc)(const FSSpec& file, const char* args,long flags);
 typedef		nsresult (*XPI_ExitProc)();
 
@@ -247,7 +247,7 @@ RunAllXPIs(short xpiVRefNum, long xpiDirID, short vRefNum, long dirID)
     }
 
 	ERR_CHECK_RET(LoadXPIStub(&xpi_initProc, &xpi_installProc, &xpi_exitProc, &connID, xpiStubDirSpec), err);
-	XPI_ERR_CHECK(xpi_initProc( xpiStubDirSpec, tgtDirSpec, xpicbProgress ));
+	XPI_ERR_CHECK(xpi_initProc( xpiStubDirSpec, tgtDirSpec, NULL, xpicbProgress ));
 	    
 	// init overall xpi indicator
 	numXPIs = CountSelectedXPIs();
diff --git a/mozilla/xpinstall/wizard/unix/src2/nsXIEngine.cpp b/mozilla/xpinstall/wizard/unix/src2/nsXIEngine.cpp
index 038d336f325..e2389545131 100644
--- a/mozilla/xpinstall/wizard/unix/src2/nsXIEngine.cpp
+++ b/mozilla/xpinstall/wizard/unix/src2/nsXIEngine.cpp
@@ -364,7 +364,7 @@ printf("DEBUG: libpath = >>%s<<\n", libpath);
 	}
     DUMP("xpistub symbols loaded");
 
-    rv = aStub->fn_init(aDestination, ProgressCallback);
+    rv = aStub->fn_init(aDestination, NULL, ProgressCallback);
 
 #ifdef DEBUG
 printf("DEBUG: XPI_Init returned 0x%.8X\n", rv);
diff --git a/mozilla/xpinstall/wizard/unix/src2/nsXIEngine.h b/mozilla/xpinstall/wizard/unix/src2/nsXIEngine.h
index b0db225bab9..7aeb5905346 100644
--- a/mozilla/xpinstall/wizard/unix/src2/nsXIEngine.h
+++ b/mozilla/xpinstall/wizard/unix/src2/nsXIEngine.h
@@ -45,7 +45,8 @@
  *   XPI Stub Glue
  *------------------------------------------------------------------------*/
 typedef nsresult (*pfnXPI_Init) 
-                 (const char *aProgramDir, pfnXPIProgress progressCB);
+                 (const char *aProgramDir, const char *aLogName,
+                  pfnXPIProgress progressCB);
 typedef nsresult (*pfnXPI_Install) 
                  (const char *file, const char *args, long flags);
 typedef void     (*pfnXPI_Exit)();