Added sanity check to insure that a valid JSRuntime was found before passing it to JS_NewContext. Bug 73491. r=mcafee,timeless. sr=alefc.

modules/libpref/src/prefapi.c

@@ -283,7 +283,11 @@ PRBool PREF_Init(const char *filename)
         return PR_FALSE;
 
     if (!gMochaTaskState)
+    {
         gMochaTaskState = PREF_GetJSRuntime();
+        if (!gMochaTaskState)
+            return PR_FALSE;
+    }
 
     if (!gMochaContext)
     {

modules/libpref/src/prefapi.cpp

@@ -283,7 +283,11 @@ PRBool PREF_Init(const char *filename)
         return PR_FALSE;
 
     if (!gMochaTaskState)
+    {
         gMochaTaskState = PREF_GetJSRuntime();
+        if (!gMochaTaskState)
+            return PR_FALSE;
+    }
 
     if (!gMochaContext)
     {