From f953b982859c43add1e035ab6346c59b2a43cc5b Mon Sep 17 00:00:00 2001
From: artscoop <artscoop93.info@gmail.com>
Date: Wed, 4 Mar 2015 22:40:04 +0100
Subject: [PATCH] Try to fix tests

Choked on roundtrip, where a P;1 image was returned instead of a 1 image.
---
 PIL/BmpImagePlugin.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/PIL/BmpImagePlugin.py b/PIL/BmpImagePlugin.py
index d6457f1e2..755cfb0fc 100644
--- a/PIL/BmpImagePlugin.py
+++ b/PIL/BmpImagePlugin.py
@@ -171,8 +171,13 @@ class BmpImageFile(ImageFile.ImageFile):
             else:
                 padding = file_info['palette_padding']
                 palette = read(padding * file_info['colors'])
+                greyscale = True
+                indices = (0, 255) if file_info['colors'] == 2 else list(range(file_info['colors']))
                 #------------------- Check if greyscale and ignore palette if so
-                greyscale = all([palette[ind] == palette[ind+1] == palette[ind+2] == ind / padding for ind in range(0, len(palette), padding)])
+                for ind in indices:
+                    rgb = palette[ind*padding:ind*padding + 3]
+                    if rgb != o8(ind) * 3:
+                        greyscale = False
                 #--------- If all colors are grey, white or black, ditch palette
                 if greyscale:
                     self.mode = "1" if file_info['colors'] == 2 else "L"