From 99c4dfffc2ccca1bf3b22e1bbcf1603c61d24ed8 Mon Sep 17 00:00:00 2001
From: gorhill <rhill@raymondhill.net>
Date: Wed, 28 Oct 2015 09:35:13 -0400
Subject: [PATCH] this fixes #876

---
 platform/firefox/frameModule.js | 10 +++++-----
 platform/firefox/vapi-client.js | 14 ++++++++++++--
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/platform/firefox/frameModule.js b/platform/firefox/frameModule.js
index 37de2b535..d952b7dc1 100644
--- a/platform/firefox/frameModule.js
+++ b/platform/firefox/frameModule.js
@@ -258,12 +258,12 @@ var contentObserver = {
 
             sandbox.injectScript = function(script) {
                 var svc = Services;
-                if ( svc !== undefined ) {
-                    svc.scriptloader.loadSubScript(script, sandbox);
-                } else {
-                    // Sandbox appears void.
-                    // I've seen this happens, need to investigate why.
+                // Sandbox appears void.
+                // I've seen this happens, need to investigate why.
+                if ( svc === undefined ) {
+                    return;
                 }
+                svc.scriptloader.loadSubScript(script, sandbox);
             };
 
             // The goal is to have content scripts removed from web pages. This
diff --git a/platform/firefox/vapi-client.js b/platform/firefox/vapi-client.js
index b8715e820..abbc59957 100644
--- a/platform/firefox/vapi-client.js
+++ b/platform/firefox/vapi-client.js
@@ -116,10 +116,20 @@ vAPI.messaging = {
                 return;
             }
             var details = msg.details;
-            if ( !details.allFrames && window !== window.top ) {
+            if ( details.allFrames !== true && window !== window.top ) {
                 return;
             }
-            self.injectScript(details.file);
+            // https://github.com/gorhill/uBlock/issues/876
+            // Enforce `details.runAt`. Default to `document_end`.
+            if ( details.runAt === 'document_start' || document.readyState !== 'loading' ) {
+                self.injectScript(details.file);
+                return;
+            }
+            var injectScriptDelayed = function() {
+                document.removeEventListener('DOMContentLoaded', injectScriptDelayed);
+                self.injectScript(details.file);
+            };
+            document.addEventListener('DOMContentLoaded', injectScriptDelayed);
             return;
         }
         if ( msg.cmd === 'shutdownSandbox' ) {