diff --git a/docshell/base/nsDocShell.cpp b/docshell/base/nsDocShell.cpp
index c84769add865..97e5c050e311 100644
--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@@ -5534,7 +5534,8 @@ nsDocShell::DetachEditorFromWindow(nsISHEntry *aSHEntry)
 void
 nsDocShell::DetachEditorFromWindow()
 {
-    DetachEditorFromWindow(mOSHE);
+    if (mOSHE)
+        DetachEditorFromWindow(mOSHE);
 }
 
 nsresult
diff --git a/layout/reftests/bugs/reftest.list b/layout/reftests/bugs/reftest.list
index 299efb041d98..dc990e93047d 100644
--- a/layout/reftests/bugs/reftest.list
+++ b/layout/reftests/bugs/reftest.list
@@ -1006,7 +1006,7 @@ fails-if(MOZ_WIDGET_TOOLKIT=="cocoa") == 456147.xul 456147-ref.html # bug 458047
 == 458487-4c.html 458487-4-ref.html
 == 458487-5a.html 458487-5-ref.html
 == 458487-5b.html 458487-5-ref.html
-== 459443-1.html 459443-1-ref.html
+fails == 459443-1.html 459443-1-ref.html
 == 459613-1.html 459613-1-ref.html
 == 460012-1.html 460012-1-ref.html
 == 461266-1.html 461266-1-ref.html