Merge pull request #1529 from atom/privilege-escalation

Ask for privilege escalation when writing file on OS X

package.json

@@ -43,6 +43,7 @@
     "pegjs": "0.8.0",
     "property-accessors": "1.x",
     "q": "1.0.x",
+    "runas": "0.4.0",
     "scandal": "0.14.0",
     "season": "1.x",
     "semver": "1.1.4",

src/file.coffee

@@ -5,6 +5,7 @@ Q = require 'q'
 {Emitter} = require 'emissary'
 _ = require 'underscore-plus'
 fs = require 'fs-plus'
+runas = require 'runas'
 
 # Public: Represents an individual file.
 #
@@ -60,8 +61,8 @@ class File
   # Public: Overwrites the file with the given String.
   write: (text) ->
     previouslyExisted = @exists()
+    @writeFileWithPrivilegeEscalationSync(@getPath(), text)
     @cachedContents = text
-    fs.writeFileSync(@getPath(), text)
     @subscribeToNativeChangeEvents() if not previouslyExisted and @hasSubscriptions()
 
   # Deprecated
@@ -122,6 +123,21 @@ class File
   getDigest: ->
     @digest ? @setDigest(@readSync())
 
+  # Writes the text to specified path.
+  #
+  # Privilege escalation would be asked when current user doesn't have
+  # permission to the path.
+  writeFileWithPrivilegeEscalationSync: (path, text) ->
+    try
+      fs.writeFileSync(path, text)
+    catch error
+      if error.code is 'EACCES' and process.platform is 'darwin'
+        authopen = '/usr/libexec/authopen'  # man 1 authopen
+        unless runas(authopen, ['-w', '-c', path], stdin: text) is 0
+          throw error
+      else
+        throw error
+
   handleNativeChangeEvent: (eventType, path) ->
     if eventType is "delete"
       @unsubscribeFromNativeChangeEvents()

src/text-buffer.coffee

@@ -194,8 +194,8 @@ class TextBuffer extends TextBufferCore
 
     @emit 'will-be-saved', this
     @setPath(filePath)
-    @cachedDiskContents = @getText()
     @file.write(@getText())
+    @cachedDiskContents = @getText()
     @conflict = false
     @emitModifiedStatusChanged(false)
     @emit 'saved', this