1 files changed, 63 insertions, 51 deletions

diff --git a/src/shell.js b/src/shell.js
index 1f987926..bac4eaa3 100644
--- a/src/shell.js
+++ b/src/shell.js
@@ -1,8 +1,31 @@
-try {
-  this['Module'] = Module;
-  Module.test;
-} catch(e) {
-  this['Module'] = Module = {};
+// The Module object: Our interface to the outside world. We import
+// and export values on it, and do the work to get that through
+// closure compiler if necessary. There are various ways Module can be used:
+// 1. Not defined. We create it here
+// 2. A function parameter, function(Module) { ..generated code.. }
+// 3. pre-run appended it, var Module = {}; ..generated code..
+// 4. External script tag defines var Module.
+// We need to do an eval in order to handle the closure compiler
+// case, where this code here is minified but Module was defined
+// elsewhere (e.g. case 4 above). We also need to check if Module
+// already exists (e.g. case 3 above).
+// Note that if you want to run closure, and also to use Module
+// after the generated code, you will need to define   var Module = {};
+// before the code. Then that object will be used in the code, and you
+// can continue to use Module afterwards as well.
+var Module;
+if (!Module) Module = eval('(function() { try { return {{{ EXPORT_NAME }}} || {} } catch(e) { return {} } })()');
+
+// Sometimes an existing Module object exists with properties
+// meant to overwrite the default module functionality. Here
+// we collect those properties and reapply _after_ we configure
+// the current environment's defaults to avoid having to be so
+// defensive during initialization.
+var moduleOverrides = {};
+for (var key in Module) {
+  if (Module.hasOwnProperty(key)) {
+    moduleOverrides[key] = Module[key];
+  }
 }
 
 // The environment setup code below is customized to use Module.
@@ -43,14 +66,11 @@ if (ENVIRONMENT_IS_NODE) {
     globalEval(read(f));
   };
 
-  if (!Module['arguments']) {
-    Module['arguments'] = process['argv'].slice(2);
-  }
+  Module['arguments'] = process['argv'].slice(2);
 
   module.exports = Module;
 }
-
-if (ENVIRONMENT_IS_SHELL) {
+else if (ENVIRONMENT_IS_SHELL) {
   Module['print'] = print;
   if (typeof printErr != 'undefined') Module['printErr'] = printErr; // not present in v8 or older sm
 
@@ -59,34 +79,15 @@ if (ENVIRONMENT_IS_SHELL) {
     return read(f, 'binary');
   };
 
-  if (!Module['arguments']) {
-    if (typeof scriptArgs != 'undefined') {
-      Module['arguments'] = scriptArgs;
-    } else if (typeof arguments != 'undefined') {
-      Module['arguments'] = arguments;
-    }
-  }
-  
-  this['{{{ EXPORT_NAME }}}'] = Module;
-}
-
-if (ENVIRONMENT_IS_WEB && !ENVIRONMENT_IS_WORKER) {
-  if (!Module['print']) {
-    Module['print'] = function(x) {
-      console.log(x);
-    };
-  }
-
-  if (!Module['printErr']) {
-    Module['printErr'] = function(x) {
-      console.log(x);
-    };
+  if (typeof scriptArgs != 'undefined') {
+    Module['arguments'] = scriptArgs;
+  } else if (typeof arguments != 'undefined') {
+    Module['arguments'] = arguments;
   }
 
   this['{{{ EXPORT_NAME }}}'] = Module;
 }
-
-if (ENVIRONMENT_IS_WEB || ENVIRONMENT_IS_WORKER) {
+else if (ENVIRONMENT_IS_WEB || ENVIRONMENT_IS_WORKER) {
   Module['read'] = function(url) {
     var xhr = new XMLHttpRequest();
     xhr.open('GET', url, false);
@@ -94,28 +95,33 @@ if (ENVIRONMENT_IS_WEB || ENVIRONMENT_IS_WORKER) {
     return xhr.responseText;
   };
 
-  if (!Module['arguments']) {
-    if (typeof arguments != 'undefined') {
-      Module['arguments'] = arguments;
-    }
+  if (typeof arguments != 'undefined') {
+    Module['arguments'] = arguments;
   }
-}
 
-if (ENVIRONMENT_IS_WORKER) {
-  // We can do very little here...
-  var TRY_USE_DUMP = false;
-  if (!Module['print']) {
+  if (ENVIRONMENT_IS_WEB) {
+    Module['print'] = function(x) {
+      console.log(x);
+    };
+
+    Module['printErr'] = function(x) {
+      console.log(x);
+    };
+
+    this['{{{ EXPORT_NAME }}}'] = Module;
+  } else if (ENVIRONMENT_IS_WORKER) {
+    // We can do very little here...
+    var TRY_USE_DUMP = false;
     Module['print'] = (TRY_USE_DUMP && (typeof(dump) !== "undefined") ? (function(x) {
       dump(x);
     }) : (function(x) {
       // self.postMessage(x); // enable this if you want stdout to be sent as messages
     }));
-  }
 
-  Module['load'] = importScripts;
+    Module['load'] = importScripts;
+  }
 }
-
-if (!ENVIRONMENT_IS_WORKER && !ENVIRONMENT_IS_WEB && !ENVIRONMENT_IS_NODE && !ENVIRONMENT_IS_SHELL) {
+else {
   // Unreachable because SHELL is dependant on the others
   throw 'Unknown runtime environment. Where are we?';
 }
@@ -144,10 +150,16 @@ Module.print = Module['print'];
 Module.printErr = Module['printErr'];
 
 // Callbacks
-if (!Module['preRun']) Module['preRun'] = [];
-if (!Module['postRun']) Module['postRun'] = [];
+Module['preRun'] = [];
+Module['postRun'] = [];
 
-  {{BODY}}
+// Merge back in the overrides
+for (var key in moduleOverrides) {
+  if (moduleOverrides.hasOwnProperty(key)) {
+    Module[key] = moduleOverrides[key];
+  }
+}
 
-  // {{MODULE_ADDITIONS}}
+{{BODY}}
 
+// {{MODULE_ADDITIONS}}