diff --git a/common/content/dactyl.js b/common/content/dactyl.js
index c53cb34b..0e3e10a1 100644
--- a/common/content/dactyl.js
+++ b/common/content/dactyl.js
@@ -380,15 +380,16 @@ var Dactyl = Module("dactyl", XPCOM(Ci.nsISupportsWeakReference, ModuleBase), {
     },
 
     userEval: function (str, context, fileName, lineNumber) {
+        let ctxt;
         if (jsmodules.__proto__ != window)
             str = "with (window) { with (modules) { (this.eval || eval)(" + str.quote() + ") } }";
 
         if (fileName == null)
             if (io.sourcing && io.sourcing.file[0] !== "[")
-                ({ file: fileName, line: lineNumber }) = io.sourcing;
+                ({ file: fileName, line: lineNumber, context: ctxt }) = io.sourcing;
             else try {
                 if (!context)
-                    context = userContext;
+                    context = userContext || ctxt;
 
                 context[EVAL_ERROR] = null;
                 context[EVAL_STRING] = str;
@@ -411,7 +412,7 @@ var Dactyl = Module("dactyl", XPCOM(Ci.nsISupportsWeakReference, ModuleBase), {
             }
 
         if (!context)
-            context = _userContext;
+            context = _userContext || ctxt;
         return Cu.evalInSandbox(str, context, "1.8", fileName, lineNumber);
     },
 
diff --git a/common/content/mappings.js b/common/content/mappings.js
index 1beae7bb..3e86257c 100644
--- a/common/content/mappings.js
+++ b/common/content/mappings.js
@@ -515,7 +515,7 @@ var Mappings = Module("mappings", {
                             description: "Accept a count before the requisite key press"
                         },
                         {
-                            names: ["-description", "-d"],
+                            names: ["-description", "-desc", "-d"],
                             description: "A description of this mapping",
                             default: "User-defined mapping",
                             type: CommandOption.STRING
diff --git a/common/modules/base.jsm b/common/modules/base.jsm
index 1de0923f..da094eff 100644
--- a/common/modules/base.jsm
+++ b/common/modules/base.jsm
@@ -1214,6 +1214,15 @@ update(iter, {
             func.call(self, val);
     },
 
+    indexOf: function indexOf(iter, elem) {
+        let i = 0;
+        for (let item in iter) {
+            if (item == elem)
+                return i;
+            i++;
+        }
+    },
+
     /**
      * Returns the array that results from applying *func* to each property of
      * *obj*.
diff --git a/common/modules/io.jsm b/common/modules/io.jsm
index d49f2349..e8fb057f 100644
--- a/common/modules/io.jsm
+++ b/common/modules/io.jsm
@@ -185,8 +185,10 @@ var IO = Module("io", {
                     else if (/\.css$/.test(filename))
                         styles.registerSheet(uri.spec, false, true);
                     else {
+                        if (!(file.path in plugins))
+                            plugins[file.path] = modules.newContext(modules.userContext);
                         modules.commands.execute(file.read(), null, silent || "loud", null,
-                            { file: file.path, line: 1 });
+                            { file: file.path, line: 1, context: plugins[file.path] });
                     }
 
                     if (this._scriptNames.indexOf(file.path) == -1)
diff --git a/common/modules/javascript.jsm b/common/modules/javascript.jsm
index ab76a98a..9d83a52f 100644
--- a/common/modules/javascript.jsm
+++ b/common/modules/javascript.jsm
@@ -478,7 +478,7 @@ var JavaScript = Module("javascript", {
                 if (obj.length) {
                     let func = obj[0][0][funcName];
                     if (callable(func)) {
-                        let [, prefix, args] = /^(function .*?)\((.*)?\)/.exec(Function.prototype.toString.call(func));
+                        let [, prefix, args] = /^(function .*?)\((.*?)\)/.exec(Function.prototype.toString.call(func));
                         let n = this._get(i).comma.length;
                         args = template.map(Iterator(args.split(", ")),
                             function ([i, arg]) <span highlight={i == n ? "Filter" : ""}>{arg}</span>,