Use hash instead of query string for parameters

This allows the pathToOpen to be changed when the project
path changes.

Previously if the untitled window file was saved, the project
path would be forever associated with the undefined window.

Now when the project path changes, the pathToOpen changes so
that the state is persisted to the project area and the untitled
window never has a project.

src/app/atom.coffee

@@ -17,6 +17,13 @@ window.atom =
   getPathToOpen: ->
     window.location.params.pathToOpen
 
+  setPathToOpen: (pathToOpen) ->
+    window.location.params.pathToOpen = pathToOpen
+    hashSegments = []
+    for name, value of window.location.params
+      hashSegments.push("#{encodeURIComponent(name)}=#{encodeURIComponent(value)}")
+    window.location.hash = '#' + hashSegments.join('&')
+
   getPackageState: (name) ->
     @packageStates[name]
 

src/app/window.coffee

@@ -128,8 +128,11 @@ window.deserializeEditorWindow = ->
 
   window.git = Git.open(project.getPath())
   project.on 'path-changed', ->
+    projectPath = project.getPath()
+    atom.setPathToOpen(projectPath)
+
     window.git?.destroy()
-    window.git = Git.open(project.getPath())
+    window.git = Git.open(projectPath)
 
 window.deserializeConfigWindow = ->
   ConfigView = require 'config-view'

src/atom-window.coffee

@@ -12,7 +12,7 @@ class AtomWindow
     @browserWindow = new BrowserWindow show: false, title: 'Atom'
     @handleEvents()
 
-    url = "file://#{resourcePath}/static/index.html?bootstrapScript=#{bootstrapScript}&resourcePath=#{resourcePath}"
+    url = "file://#{resourcePath}/static/index.html#bootstrapScript=#{bootstrapScript}&resourcePath=#{resourcePath}"
     url += "&pathToOpen=#{@pathToOpen}" if @pathToOpen
     url += '&exitWhenDone=1' if exitWhenDone
 

static/index.html

@@ -5,13 +5,13 @@
 
   <script>
     window.location.params = {}
-    var params = window.location.search.substring(1).split('&')
+    var params = window.location.hash.substring(1).split('&')
     params.forEach(function(param) {
-      var pair = param.split("=")
+      var pair = param.split("=");
       window.location.params[decodeURIComponent(pair[0])] = decodeURIComponent(pair[1]);
     });
 
-    window.resourcePath = window.location.params.resourcePath
+    window.resourcePath = window.location.params.resourcePath;
     var bootstrapScript = window.location.params.bootstrapScript;
 
     window.onload = function() {