2 files changed, 17 insertions, 7 deletions
diff --git a/toolkit/components/prompts/src/nsPrompter.js b/toolkit/components/prompts/src/nsPrompter.js
index 26efe28cc..0503b5925 100644
--- a/toolkit/components/prompts/src/nsPrompter.js
+++ b/toolkit/components/prompts/src/nsPrompter.js
@@ -369,7 +369,13 @@ function openTabPrompt(domWin, tabPrompt, args) {
                          .getInterface(Ci.nsIDocShell);
     let inPermitUnload = docShell.contentViewer && docShell.contentViewer.inPermitUnload;
     let eventDetail = Cu.cloneInto({tabPrompt: true, inPermitUnload}, domWin);
-    PromptUtils.fireDialogEvent(domWin, "DOMWillOpenModalDialog", null, eventDetail);
+    let allowFocusSwitch = true;
+    try {
+      allowFocusSwitch = Services.prefs.getBoolPref("prompts.tab_modal.focusSwitch");
+    } catch(e) {}
+    
+    if (allowFocusSwitch)    
+      PromptUtils.fireDialogEvent(domWin, "DOMWillOpenModalDialog", null, eventDetail);
 
     let winUtils = domWin.QueryInterface(Ci.nsIInterfaceRequestor)
                          .getInterface(Ci.nsIDOMWindowUtils);
@@ -395,8 +401,8 @@ function openTabPrompt(domWin, tabPrompt, args) {
         frameMM.removeEventListener("pagehide", pagehide, true);
 
         winUtils.leaveModalState();
-
-        PromptUtils.fireDialogEvent(domWin, "DOMModalDialogClosed");
+        if (allowFocusSwitch)
+          PromptUtils.fireDialogEvent(domWin, "DOMModalDialogClosed");
     }
 
     frameMM.addEventListener("pagehide", pagehide, true);
diff --git a/toolkit/mozapps/extensions/internal/LightweightThemeImageOptimizer.jsm b/toolkit/mozapps/extensions/internal/LightweightThemeImageOptimizer.jsm
index a5bc23ccd..a9201c3da 100644
--- a/toolkit/mozapps/extensions/internal/LightweightThemeImageOptimizer.jsm
+++ b/toolkit/mozapps/extensions/internal/LightweightThemeImageOptimizer.jsm
@@ -59,10 +59,14 @@ var ImageCropper = {
       return aImageURL;
     }
 
-    if (Services.prefs.getBoolPref("lightweightThemes.animation.enabled")) {
-      //Don't crop if animated
-      return aImageURL;
-    }   
+    try {
+      if (Services.prefs.getBoolPref("lightweightThemes.animation.enabled")) {
+        //Don't crop if animated
+        return aImageURL;
+      }
+    } catch(e) { 
+      // Continue of pref doesn't exist.
+    }
 
     // Generate the cropped image's file name using its
     // base name and the current screen size.