diff --git a/content/buffer.js b/content/buffer.js
index e2fb7426..3c494bb1 100644
--- a/content/buffer.js
+++ b/content/buffer.js
@@ -1312,31 +1312,14 @@ function Buffer() //{{{
                     docUrl, docCharset, reference, "selection");
         },
 
-        // url is optional
         viewSource: function (url, useExternalEditor)
         {
             url = url || buffer.URL;
 
             if (useExternalEditor)
-            {
-                // TODO: make that a helper function
-                // TODO: save return value in v:shell_error
-                var editor = options["editor"];
-                var args = commands.parseArgs(editor, [], "*", true);
-                if (args.length < 1)
-                {
-                    liberator.echoerr("No editor specified");
-                    return;
-                }
-
-                var prog = args.shift();
-                args.push(url);
-                liberator.callFunctionInThread(null, io.run, prog, args, true);
-            }
+                editor.editFileExternally(url);
             else
-            {
                 liberator.open("view-source:" + url);
-            }
         },
 
         zoomIn: function (steps, fullZoom)
diff --git a/content/editor.js b/content/editor.js
index aee4c8e3..d911ee25 100644
--- a/content/editor.js
+++ b/content/editor.js
@@ -295,7 +295,7 @@ function Editor() //{{{
 
     mappings.add([modes.INSERT, modes.TEXTAREA, modes.COMPOSE],
         ["<C-i>"], "Edit text field with an external editor",
-        function () { editor.editWithExternalEditor(); });
+        function () { editor.editFieldExternally(); });
 
     // FIXME: <esc> does not work correctly
     mappings.add([modes.INSERT],
@@ -794,14 +794,32 @@ function Editor() //{{{
             return -1;
         },
 
-        // TODO: clean up with 2 functions for textboxes and currentEditor?
-        editWithExternalEditor: function ()
+        editFileExternally: function (path)
         {
+            // TODO: save return value in v:shell_error
+            let args = commands.parseArgs(options["editor"], [], "*", true);
+
+            if (args.length < 1)
+            {
+                liberator.echoerr("No editor specified");
+                return;
+            }
+
+            args.push(path);
+            liberator.callFunctionInThread(null, io.run, args.shift(), args, true);
+        },
+
+        // TODO: clean up with 2 functions for textboxes and currentEditor?
+        editFieldExternally: function ()
+        {
+            if (!options["editor"])
+                return false;
+
             var textBox = null;
             if (!(config.isComposeWindow))
                 textBox = document.commandDispatcher.focusedElement;
 
-            var text = "";
+            var text = ""; // XXX
             if (textBox)
                 text = textBox.value;
             else if (typeof GetCurrentEditor == "function") // Thunderbird composer
@@ -809,14 +827,6 @@ function Editor() //{{{
             else
                 return false;
 
-            var editor = options["editor"];
-            var args = commands.parseArgs(editor, [], "*", true);
-            if (args.length < 1)
-            {
-                liberator.echoerr("No editor specified");
-                return false;
-            }
-
             try
             {
                 var tmpfile = io.createTempFile();
@@ -836,9 +846,6 @@ function Editor() //{{{
                 return false;
             }
 
-            var prog = args.shift();
-            args.push(tmpfile.path);
-
             if (textBox)
             {
                 textBox.setAttribute("readonly", "true");
@@ -847,8 +854,7 @@ function Editor() //{{{
                 textBox.style.backgroundColor = "#bbbbbb";
             }
 
-            // TODO: save return value in v:shell_error
-            liberator.callFunctionInThread(null, io.run, prog, args, true);
+            this.editFileExternally(tmpfile.path);
 
             if (textBox)
                 textBox.removeAttribute("readonly");
diff --git a/content/muttator.js b/content/muttator.js
index f37759bd..45aa4c7c 100644
--- a/content/muttator.js
+++ b/content/muttator.js
@@ -131,7 +131,7 @@ const config = { //{{{
             // TODO: move mappings elsewhere, probably compose.js
             mappings.add([modes.COMPOSE],
                 ["e"], "Edit message",
-                function () { editor.editWithExternalEditor(); });
+                function () { editor.editFieldExternally(); });
 
             mappings.add([modes.COMPOSE],
                 ["y"], "Send message now",
@@ -178,7 +178,7 @@ const config = { //{{{
                     if (options["autoexternal"] && !window.messageWasEditedExternally/* && !gMsgCompose.recycledWindow*/)
                     {
                         window.messageWasEditedExternally = true;
-                        editor.editWithExternalEditor();
+                        editor.editFieldExternally();
                     }
 
                 },