diff --git a/mozilla/xpinstall/src/nsInstall.cpp b/mozilla/xpinstall/src/nsInstall.cpp
index 3009d171a86..193ff36c6ba 100644
--- a/mozilla/xpinstall/src/nsInstall.cpp
+++ b/mozilla/xpinstall/src/nsInstall.cpp
@@ -513,7 +513,7 @@ nsInstall::AddSubcomponent(const nsString& aRegName,
       tempTargetName = aJarSource;
     
     if (qualifiedVersion == "")
-        qualifiedVersion.SetString("0.0.0.0");   	
+        qualifiedVersion.Assign("0.0.0.0");   	
 
 
     if ( aRegName.Equals("") ) 
diff --git a/mozilla/xpinstall/src/nsInstallFolder.cpp b/mozilla/xpinstall/src/nsInstallFolder.cpp
index 02e5a8dc5b8..f88282ff21a 100644
--- a/mozilla/xpinstall/src/nsInstallFolder.cpp
+++ b/mozilla/xpinstall/src/nsInstallFolder.cpp
@@ -165,7 +165,7 @@ nsInstallFolder::GetDirectoryPath(nsString& aDirectoryPath)
     if (mFileSpec != nsnull)
     {
         // We want the a NATIVE path.
-       aDirectoryPath.SetString(mFileSpec->GetCString());
+       aDirectoryPath.Assign(mFileSpec->GetCString());
 
        if (mFileSpec->IsDirectory())
        {
diff --git a/mozilla/xpinstall/src/nsInstallTrigger.cpp b/mozilla/xpinstall/src/nsInstallTrigger.cpp
index a0c3b7f23e3..e37cf738148 100644
--- a/mozilla/xpinstall/src/nsInstallTrigger.cpp
+++ b/mozilla/xpinstall/src/nsInstallTrigger.cpp
@@ -420,7 +420,7 @@ nsInstallTrigger::GetVersion(const nsString& component, nsString& version)
 
     status = VR_GetVersion( tempCString, &cVersion );
 
-    version.SetString("");
+    version.Truncate();
 
     /* if we got the version */
     if ( status == REGERR_OK && VR_ValidateComponent( tempCString ) == REGERR_OK) 
@@ -451,7 +451,7 @@ nsInstallTrigger::CreateTempFileFromURL(const nsString& aURL, nsString& tempFile
 
     if ( aURL.EqualsIgnoreCase("file:/", 6) )
     {       
-        tempFileString.SetString( nsNSPRPath(nsFileURL(aURL)) );
+        tempFileString.Assign( nsNSPRPath(nsFileURL(aURL)) );
     }
     else
     {
@@ -482,7 +482,7 @@ nsInstallTrigger::CreateTempFileFromURL(const nsString& aURL, nsString& tempFile
 
         tempFile.MakeUnique();
 
-        tempFileString.SetString( nsNSPRPath( nsFilePath(tempFile) ) );
+        tempFileString.Assign( nsNSPRPath( nsFilePath(tempFile) ) );
     }
 }
 
diff --git a/mozilla/xpinstall/src/nsInstallUninstall.cpp b/mozilla/xpinstall/src/nsInstallUninstall.cpp
index 0b297fad2b8..2e3501174ae 100644
--- a/mozilla/xpinstall/src/nsInstallUninstall.cpp
+++ b/mozilla/xpinstall/src/nsInstallUninstall.cpp
@@ -50,14 +50,14 @@ nsInstallUninstall::nsInstallUninstall( nsInstall* inInstall,
         return;
     }
     
-    mRegName.SetString(regName);
+    mRegName.Assign(regName);
 
     char* userName = (char*)PR_Malloc(MAXREGPATHLEN);
     PRInt32 err = VR_GetUninstallUserName( (char*) (const char*) nsAutoCString(regName), 
                                            userName, 
                                            MAXREGPATHLEN );
     
-    mUIName.SetString(userName);
+    mUIName.Assign(userName);
     
     if (err != REGERR_OK)
     {
diff --git a/mozilla/xpinstall/src/nsInstallVersion.cpp b/mozilla/xpinstall/src/nsInstallVersion.cpp
index 5e146845ef6..78ba635b933 100644
--- a/mozilla/xpinstall/src/nsInstallVersion.cpp
+++ b/mozilla/xpinstall/src/nsInstallVersion.cpp
@@ -272,7 +272,7 @@ nsInstallVersion::ToString(nsString& aReturn)
     char *result=NULL;
     result = PR_sprintf_append(result, "%d.%d.%d.%d", major, minor, release, build);
     
-    aReturn.SetString(result);
+    aReturn.Assign(result);
 
     PR_FREEIF(result);
 
diff --git a/mozilla/xpinstall/src/nsJSInstall.cpp b/mozilla/xpinstall/src/nsJSInstall.cpp
index 93879d2e814..b3219cfb629 100644
--- a/mozilla/xpinstall/src/nsJSInstall.cpp
+++ b/mozilla/xpinstall/src/nsJSInstall.cpp
@@ -218,15 +218,15 @@ void ConvertJSValToStr(nsString&  aString,
 
   if((jsstring = JS_ValueToString(aContext, aValue)) != nsnull)
   {
-    aString.SetString(JS_GetStringChars(jsstring));
+    aString.Assign(JS_GetStringChars(jsstring));
     if (aString.EqualsIgnoreCase("null"))
     {
-        aString.SetString("");
+        aString.Truncate();
     }
   }
   else
   {
-    aString.SetString("");
+    aString.Truncate();
   }
 }