From 95182149806ce9c61a2dce39d0876a8cc1b25c31 Mon Sep 17 00:00:00 2001
From: wiredfool <eric-github@soroos.net>
Date: Tue, 25 Mar 2014 21:42:04 -0700
Subject: [PATCH 1/3] Tests for #544

---
 Tests/test_image_convert.py  | 8 ++++++++
 Tests/test_image_quantize.py | 7 ++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/Tests/test_image_convert.py b/Tests/test_image_convert.py
index fd3d39bc5..d3bdb519c 100644
--- a/Tests/test_image_convert.py
+++ b/Tests/test_image_convert.py
@@ -46,5 +46,13 @@ def test_16bit_workaround():
     im = Image.open('Tests/images/16bit.cropped.tif')
     _test_float_conversion(im.convert('I'))
     
+def test_rgba_p():
+    im = lena('RGBA')
+    im.putalpha(lena('L'))
 
+    converted = im.convert('P')
+    comparable = converted.convert('RGBA')
+
+    assert_image_similar(im, comparable, 20)
+               
     
diff --git a/Tests/test_image_quantize.py b/Tests/test_image_quantize.py
index 70b5eb503..dbf68a25e 100644
--- a/Tests/test_image_quantize.py
+++ b/Tests/test_image_quantize.py
@@ -19,4 +19,9 @@ def test_octree_quantize():
     im = im.quantize(100, Image.FASTOCTREE)
     assert_image(im, "P", im.size)
 
-    assert len(im.getcolors()) == 100
\ No newline at end of file
+    assert len(im.getcolors()) == 100
+
+def test_rgba_quantize():
+    im = lena('RGBA')
+    assert_no_exception(lambda: im.quantize())
+    assert_exception(Exception, lambda: im.quantize(method=0))

From abebac25ccdb811ae6ac574f44de8dc36591645b Mon Sep 17 00:00:00 2001
From: wiredfool <eric-github@soroos.net>
Date: Tue, 25 Mar 2014 21:35:20 -0700
Subject: [PATCH 2/3] Sane quantize defaults for RGBA->P, fixes #544

---
 PIL/Image.py | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/PIL/Image.py b/PIL/Image.py
index 7713fe7d9..ed3269169 100644
--- a/PIL/Image.py
+++ b/PIL/Image.py
@@ -735,6 +735,9 @@ class Image:
             im = self.im.convert_matrix(mode, matrix)
             return self._new(im)
 
+        if mode == "P" and self.mode == "RGBA":
+            return self.quantize(colors)
+
         if mode == "P" and palette == ADAPTIVE:
             im = self.im.quantize(colors)
             new = self._new(im)
@@ -762,7 +765,7 @@ class Image:
 
         return self._new(im)
 
-    def quantize(self, colors=256, method=0, kmeans=0, palette=None):
+    def quantize(self, colors=256, method=None, kmeans=0, palette=None):
 
         # methods:
         #    0 = median cut
@@ -773,7 +776,18 @@ class Image:
         # quantizer interface in a later version of PIL.
 
         self.load()
+        
+        if method is None:
+            # defaults:
+            method = 0
+            if self.mode == 'RGBA':
+                method = 2
 
+        if self.mode == 'RGBA' and method != 2:
+            # Caller specified an invalid mode. 
+            raise ValueError('Fast Octree (method == 2) is the ' +
+                             ' only valid method for quantizing RGBA images')
+        
         if palette:
             # use palette from reference image
             palette.load()

From a190d641652c6f818a772f864054f639f65e5100 Mon Sep 17 00:00:00 2001
From: wiredfool <eric-github@soroos.net>
Date: Tue, 25 Mar 2014 21:44:28 -0700
Subject: [PATCH 3/3] Changes.rst updated

---
 CHANGES.rst | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/CHANGES.rst b/CHANGES.rst
index 38349c2d1..a839db40d 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -4,6 +4,9 @@ Changelog (Pillow)
 2.4.0 (unreleased)
 ------------------
 
+- Conversions enabled from RGBA->P, Fixes #544
+  [wiredfool]
+
 - Add more detailed error messages to Image.py 
   [larsmans]