fix for bug #363690: make historyDisabled scriptable

r=mano,dietrich

browser/components/places/tests/unit/test_history.js

@@ -81,4 +81,7 @@ function run_test() {
     //do_check_eq(node.transitionType, histsvc.TRANSITION_TYPED);
   }
   root.containerOpen = false;
+
+  // by default, browser.history_expire_days is 9
+  do_check_true(!histsvc.historyDisabled);
 }

toolkit/components/places/public/nsINavHistoryService.idl

@@ -1114,7 +1114,7 @@ interface nsINavHistoryQueryOptions : nsISupports
   nsINavHistoryQueryOptions clone();
 };
 
-[scriptable, uuid(C51F54CB-5E89-4B20-A37C-1343888935B7)]
+[scriptable, uuid(1a8df7bf-4889-4331-a521-f6c4dacd20e7)]
 interface nsINavHistoryService : nsISupports
 {
   /**
@@ -1304,6 +1304,12 @@ interface nsINavHistoryService : nsISupports
    * done changing. Should match beginUpdateBatch or bad things will happen.
    */
   void endUpdateBatch();
+
+  /** 
+   * True if history is disabled. currently, 
+   * history is disabled if the browser.history_expire_days pref is 0
+   */
+  readonly attribute boolean historyDisabled;
 };
 
 /**

toolkit/components/places/src/nsNavHistory.cpp

@@ -233,7 +233,8 @@ nsNavHistory::nsNavHistory() : mNowValid(PR_FALSE),
                                mExpireNowTimer(nsnull),
                                mExpire(this),
                                mBatchesInProgress(0),
-                               mAutoCompleteOnlyTyped(PR_FALSE)
+                               mAutoCompleteOnlyTyped(PR_FALSE),
+                               mExpireDays(0)
 {
 #ifdef LAZY_ADD
   mLazyTimerSet = PR_TRUE;
@@ -2111,6 +2112,14 @@ nsNavHistory::EndUpdateBatch()
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsNavHistory::GetHistoryDisabled(PRBool *_retval)
+{
+  NS_ENSURE_ARG_POINTER(_retval);
+  *_retval = IsHistoryDisabled();
+  return NS_OK;
+}
+
 // Browser history *************************************************************