fix for #32649. make it so an error on migration makes its way into an alert for the user.

(still more work to do when handling out of space errors.)  clean up code.

profile/pref-migrator/public/nsIPrefMigration.idl

@@ -37,7 +37,7 @@ interface nsIPrefMigration: nsISupports
   void AddProfilePaths(in string oldProfilePathStr, in string newProfilePathStr);
   void ProcessPrefs(in boolean showProgressAsModalWindow);
   void ProcessPrefsFromJS();
-  void GetError(out PRUint32 error);
+  void GetError();
 
   /**
    * this should be in a seperate interface

profile/pref-migrator/resources/content/profileMigrationProgress.js

@@ -36,15 +36,15 @@ function onLoad(oldProfilePath, newProfilePath) {
   var prefmigrator = Components.classes['component://netscape/profile/migration'].createInstance(Components.interfaces.nsIPrefMigration);
   if (prefmigrator) 
   {
-	 dump("-----  Migrating prefs\n");
-     retval = prefmigrator.ProcessPrefsFromJS();
-	 dump("-----  Migrating prefs done " + retval + "\n" );
+	dump("-----  Migrating prefs\n");
+	try {
+     		prefmigrator.ProcessPrefsFromJS();
+	}
+	catch (ex) {
+		alert("error migrating profile, possibly out of space.  ex="+ex);
+	}
+	dump("-----  Migrating prefs done " + retval + "\n" );
   }
-  else
-  {
-	  dump("-----  ERROR Migrating prefs failed create instances failed\n");
-  }
-  return retval;
 }
 
 

profile/pref-migrator/src/nsPrefMigration.cpp

@@ -251,6 +251,7 @@ nsPrefMigration::GetInstance()
 nsPrefMigration::nsPrefMigration() : m_prefs(0)
 {
   NS_INIT_REFCNT();
+  mErrorCode = NS_OK;
 }
 
 
@@ -409,15 +410,16 @@ nsPrefMigration::ProcessPrefsFromJS()  // called via js so that we can have prog
                                      PR_GLOBAL_THREAD, 
                                      PR_UNJOINABLE_THREAD,
                                      0);  
-  return NS_OK;
+
+  nsresult err = GetError();
+  return err;
 }  
     
 
 NS_IMETHODIMP
-nsPrefMigration::GetError(PRUint32 *error)
+nsPrefMigration::GetError()
 {
-  *error = mErrorCode;
-  return NS_OK;
+  return mErrorCode;
 }
 
 nsresult