From 99887a546763c950233f691cf5dd0107f38cfc81 Mon Sep 17 00:00:00 2001
From: Hugo <hugovk@users.noreply.github.com>
Date: Tue, 16 Sep 2014 16:05:22 +0300
Subject: [PATCH] Improve the error message when importing ImageGrab on
 non-Windows (#901)

---
 PIL/ImageGrab.py        |  5 ++++-
 Tests/test_imagegrab.py | 25 +++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/PIL/ImageGrab.py b/PIL/ImageGrab.py
index 9bb190934..ef0135334 100644
--- a/PIL/ImageGrab.py
+++ b/PIL/ImageGrab.py
@@ -17,6 +17,9 @@
 
 from PIL import Image
 
+import sys
+if sys.platform != "win32":
+    raise ImportError("ImageGrab is Windows only")
 
 try:
     # built-in driver (1.1.3 and later)
@@ -40,7 +43,7 @@ def grab(bbox=None):
 
 
 def grabclipboard():
-    debug = 0 # temporary interface
+    debug = 0  # temporary interface
     data = Image.core.grabclipboard(debug)
     if isinstance(data, bytes):
         from PIL import BmpImagePlugin
diff --git a/Tests/test_imagegrab.py b/Tests/test_imagegrab.py
index 13affe6b9..dd6f50fb9 100644
--- a/Tests/test_imagegrab.py
+++ b/Tests/test_imagegrab.py
@@ -1,5 +1,8 @@
 from helper import unittest, PillowTestCase
 
+import exceptions
+import sys
+
 try:
     from PIL import ImageGrab
 
@@ -19,6 +22,28 @@ except ImportError:
             self.skipTest("ImportError")
 
 
+class TestImageGrabImport(PillowTestCase):
+
+    def test_import(self):
+        # Arrange
+        exception = None
+
+        # Act
+        try:
+            from PIL import ImageGrab
+            ImageGrab.__name__  # dummy to prevent Pyflakes warning
+        except Exception as exception:
+            pass
+
+        # Assert
+        if sys.platform == 'win32':
+            self.assertIsNone(exception, None)
+        else:
+            self.assertIsInstance(exception, exceptions.ImportError)
+            self.assertEqual(exception.message,
+                             "ImageGrab is Windows only")
+
+
 if __name__ == '__main__':
     unittest.main()