From ea488282ff0d911478d3bd5b88518ad69b9c7b94 Mon Sep 17 00:00:00 2001
From: "blakeross%telocity.com" <blakeross%telocity.com>
Date: Tue, 19 Dec 2000 08:14:09 +0000
Subject: [PATCH] Fix 63170: crash in [add|remove]Observer if either argument
 is null. r=dveditz sr=alecf

---
 modules/libpref/src/nsPref.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/modules/libpref/src/nsPref.cpp b/modules/libpref/src/nsPref.cpp
index 078f5fcb157..ff48fc2b706 100644
--- a/modules/libpref/src/nsPref.cpp
+++ b/modules/libpref/src/nsPref.cpp
@@ -1217,6 +1217,9 @@ NS_IMETHODIMP nsPref::UnregisterCallback( const char* domain,
 NS_IMETHODIMP nsPref::AddObserver(const char *domain,
                                   nsIObserver *observer)
 {
+    NS_ENSURE_ARG_POINTER(domain);
+    NS_ENSURE_ARG_POINTER(observer);
+
     nsCStringKey key(domain);
     mObservers.Put(&key, observer);
     return RegisterCallback(domain, NotifyObserver, observer);
@@ -1225,6 +1228,9 @@ NS_IMETHODIMP nsPref::AddObserver(const char *domain,
 NS_IMETHODIMP nsPref::RemoveObserver(const char *domain,
                                      nsIObserver *observer)
 {
+    NS_ENSURE_ARG_POINTER(domain);
+    NS_ENSURE_ARG_POINTER(observer);
+
     nsCStringKey key(domain);
     mObservers.Remove(&key);
     return UnregisterCallback(domain, NotifyObserver, observer);