Bug 3344605. nsIPropertyBag2 should grow a non-throwing get() and hasKey(). r=darin, sr=shaver

xpcom/ds/nsHashPropertyBag.cpp

@@ -87,6 +87,22 @@ nsHashPropertyBag::Init()
     return NS_OK;
 }
 
+NS_IMETHODIMP
+nsHashPropertyBag::HasKey(const nsAString& name, PRBool *aResult)
+{
+    *aResult = mPropertyHash.Get(name, nsnull);
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsHashPropertyBag::Get(const nsAString& name, nsIVariant* *_retval)
+{
+    mPropertyHash.Get(name, _retval);
+
+    return NS_OK;
+}
+
 NS_IMETHODIMP
 nsHashPropertyBag::GetProperty(const nsAString& name, nsIVariant* *_retval)
 {

xpcom/ds/nsIPropertyBag2.idl

@@ -39,7 +39,7 @@
 
 #include "nsIPropertyBag.idl"
 
-[scriptable, uuid(9bb35f13-0096-4a31-833a-acd97001132d)]
+[scriptable, uuid(625cfd1e-da1e-4417-9ee9-dbc8e0b3fd79)]
 interface nsIPropertyBag2 : nsIPropertyBag
 {
   // Accessing a property as a different type may attempt conversion to the
@@ -61,4 +61,15 @@ interface nsIPropertyBag2 : nsIPropertyBag
   void        getPropertyAsInterface   (in AString prop,
                                         in nsIIDRef iid,
                                         [iid_is(iid), retval] out nsQIResult result);
+
+  /**
+   * This method returns null if the value does not exist,
+   * or exists but is null.
+   */
+  nsIVariant  get                      (in AString prop);
+ 
+  /**
+   * Check for the existence of a key.
+   */
+  PRBool      hasKey                   (in AString prop);
 };