Bug 906795 - safeErrorString should include a stack; r=vporof

toolkit/devtools/DevToolsUtils.js

@@ -6,12 +6,26 @@
 
 /* General utilities used throughout devtools. */
 
-/* Turn the error e into a string, without fail. */
+/**
+ * Turn the error |aError| into a string, without fail.
+ */
 this.safeErrorString = function safeErrorString(aError) {
   try {
-    var s = aError.toString();
-    if (typeof s === "string")
-      return s;
+    let errorString = aError.toString();
+    if (typeof errorString === "string") {
+      // Attempt to attach a stack to |errorString|. If it throws an error, or
+      // isn't a string, don't use it.
+      try {
+        if (aError.stack) {
+          let stack = aError.stack.toString();
+          if (typeof stack === "string") {
+            errorString += "\nStack: " + stack;
+          }
+        }
+      } catch (ee) { }
+
+      return errorString;
+    }
   } catch (ee) { }
 
   return "<failed trying to find error description>";
@@ -22,9 +36,6 @@ this.safeErrorString = function safeErrorString(aError) {
  */
 this.reportException = function reportException(aWho, aException) {
   let msg = aWho + " threw an exception: " + safeErrorString(aException);
-  if (aException.stack) {
-    msg += "\nCall stack:\n" + aException.stack;
-  }
 
   dump(msg + "\n");