diff --git a/common/content/io.js b/common/content/io.js
index 3148c30d..a40a2bd9 100644
--- a/common/content/io.js
+++ b/common/content/io.js
@@ -759,15 +759,30 @@ lookup:
         };
 
         completion.addUrlCompleter("f", "Local files", function (context, full) {
-            let match = /^(chrome:\/\/[^\/]+\/)([^/]*)$/.exec(context.filter);
+            let match = util.regexp(<![CDATA[
+                ^
+                (
+                    ((chrome|resource):\/\/)
+                    [^\/]*
+                )
+                (\/[^\/]*)?
+                $
+            ]]>).exec(context.filter);
             if (match) {
-                context.key = match[1];
-                context.advance(match[1].length);
-                context.generate = function () iter({
-                    content: "Chrome content",
-                    locale: "Locale-specific content",
-                    skin: "Theme-specific content"
-                });
+                if (!match[4]) {
+                    context.key = match[2];
+                    context.advance(match[2].length);
+                    context.generate = function () util.chromePackages.map(function (p) [p, match[1] + p + "/"]);
+                }
+                else if (match[3] === "chrome") {
+                    context.key = match[1];
+                    context.advance(match[1].length + 1);
+                    context.generate = function () iter({
+                        content: "Chrome content",
+                        locale: "Locale-specific content",
+                        skin: "Theme-specific content"
+                    });
+                }
             }
             else if (/^(\.{0,2}|~)\/|^file:/.test(context.filter) || util.getFile(context.filter) || io.isJarURL(context.filter))
                 completion.file(context, full);
diff --git a/common/modules/storage.jsm b/common/modules/storage.jsm
index 8f5cca84..c7a764b3 100644
--- a/common/modules/storage.jsm
+++ b/common/modules/storage.jsm
@@ -288,6 +288,8 @@ const File = Class("File", {
      * Iterates over the objects in this directory.
      */
     iterDirectory: function () {
+        if (!this.exists())
+            throw Error("File does not exist");
         if (!this.isDirectory())
             throw Error("Not a directory");
         for (let file in iter(this.directoryEntries))
@@ -313,32 +315,9 @@ const File = Class("File", {
      */
     read: function (encoding) {
         let ifstream = Cc["@mozilla.org/network/file-input-stream;1"].createInstance(Ci.nsIFileInputStream);
-
         ifstream.init(this, -1, 0, 0);
 
-        try {
-            if (encoding instanceof Ci.nsIOutputStream) {
-                let l, len = 0;
-                while ((l = encoding.writeFrom(ifstream, 4096)) != 0)
-                    len += l;
-                return len;
-            }
-            else {
-                var icstream = Cc["@mozilla.org/intl/converter-input-stream;1"].createInstance(Ci.nsIConverterInputStream);
-                icstream.init(ifstream, encoding || File.defaultEncoding, 4096, // 4096 bytes buffering
-                              Ci.nsIConverterInputStream.DEFAULT_REPLACEMENT_CHARACTER);
-                let buffer = [];
-                let str = {};
-                while (icstream.readString(4096, str) != 0)
-                    buffer.push(str.value);
-                return buffer.join("");
-            }
-        }
-        finally {
-            if (icstream)
-                icstream.close();
-            ifstream.close();
-        }
+        return File.readStream(ifstream, encoding);
     },
 
     /**
@@ -534,6 +513,23 @@ const File = Class("File", {
 
     expandPathList: function (list) list.map(this.expandPath),
 
+    readStream: function (ifstream, encoding) {
+        try {
+            var icstream = Cc["@mozilla.org/intl/converter-input-stream;1"].createInstance(Ci.nsIConverterInputStream);
+            icstream.init(ifstream, encoding || File.defaultEncoding, 4096, // 4096 bytes buffering
+                          Ci.nsIConverterInputStream.DEFAULT_REPLACEMENT_CHARACTER);
+            let buffer = [];
+            let str = {};
+            while (icstream.readString(4096, str) != 0)
+                buffer.push(str.value);
+            return buffer.join("");
+        }
+        finally {
+            icstream.close();
+            ifstream.close();
+        }
+    },
+
     isAbsolutePath: function (path) {
         try {
             services.File().initWithPath(path);
diff --git a/common/modules/util.jsm b/common/modules/util.jsm
index 681a97e5..d7b11554 100644
--- a/common/modules/util.jsm
+++ b/common/modules/util.jsm
@@ -104,6 +104,55 @@ const Util = Module("Util", XPCOM([Ci.nsIObserver, Ci.nsISupportsWeakReference])
             throw new FailedAssertion(message);
     },
 
+    get chromePackages() {
+        // Horrible hack.
+        let res = {};
+        function process(manifest) {
+            for each (let line in manifest.split(/\n+/)) {
+                let match = /^\s*(content|skin|locale|resource)\s+([^\s#]+)\s/.exec(line);
+                if (match)
+                    res[match[2]] = true;
+            }
+        }
+        function processJar(file) {
+            let jar = services.ZipReader(file);
+            if (jar) {
+                if (jar.hasEntry("chrome.manifest"))
+                    process(File.readStream(jar.getInputStream("chrome.manifest")));
+                jar.close();
+            }
+        }
+
+        for each (let dir in ["UChrm", "AChrom"]) {
+            dir = File(services.directory.get(dir, Ci.nsIFile));
+            if (dir.exists() && dir.isDirectory())
+                for (let file in dir.iterDirectory())
+                    if (/\.manifest$/.test(file.leafName))
+                        process(file.read());
+
+            dir = File(dir.parent);
+            if (dir.exists() && dir.isDirectory())
+                for (let file in dir.iterDirectory())
+                    if (/\.jar$/.test(file.leafName))
+                        processJar(file);
+
+            dir = dir.child("extensions");
+            if (dir.exists() && dir.isDirectory())
+                for (let ext in dir.iterDirectory()) {
+                    if (/\.xpi$/.test(ext.leafName))
+                        processJar(ext);
+                    else {
+                        if (ext.isFile())
+                            ext = File(ext.read().replace(/\n*$/, ""));
+                        let mf = ext.child("chrome.manifest");
+                        if (mf.exists())
+                            process(mf.read());
+                    }
+                }
+        }
+        return Object.keys(res).sort();
+    },
+
     /**
      * Returns a shallow copy of *obj*.
      *