Fix anonymous wrapping injection.

Broke with the previous error reporting tweak.

Refs greasemonkey#1404

components/greasemonkey.js

@@ -266,9 +266,30 @@ function registerMenuCommand(
 };
 
 function runScriptInSandbox(script, sandbox) {
-  function doEval(code, fileName) {
+  // Eval the code, with anonymous wrappers when/if appropriate.
+  function evalWithWrapper(code, fileName) {
+    // By default, unless we've explicitly been told to unwrap, do an anonymous
+    // wrapper scope.  See http://goo.gl/0sFqU for detailed reasoning.
+    if (!script.unwrap) code = GM_util.anonWrap(code);
+
     try {
       Components.utils.evalInSandbox(code, sandbox, gMaxJSVersion, fileName, 1);
+    } catch (e) {
+      if (script.unwrap && e && "return not in function" == e.message) {
+        // If we didn't wrap, but have an early return, run wrapped anyway.
+        Components.utils.evalInSandbox(
+            GM_util.anonWrap(code), sandbox, gMaxJSVersion, fileName, 1);
+      } else {
+        // Otherwise raise.
+        throw e;
+      }
+    }
+  }
+
+  // Eval the code, with a try/catch to report errors cleanly.
+  function evalWithCatch(code, fileName) {
+    try {
+      evalWithWrapper(code, fileName);
     } catch (e) {
       // Log it properly.
       GM_util.logError(e, false, fileName, e.lineNumber);
@@ -279,11 +300,11 @@ function runScriptInSandbox(script, sandbox) {
   }
 
   for (var i = 0, require = null; require = script.requires[i]; i++) {
-    if (!doEval(require.textContent, require.fileURL)) {
+    if (!evalWithCatch(require.textContent, require.fileURL)) {
       return;
     }
   }
-  doEval(script.textContent, script.fileURL);
+  evalWithCatch(script.textContent, script.fileURL);
 }
 
 function startup(aService) {