From dba38912fb1217bad9610f842c9ff5194f64ef53 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Wed, 20 Mar 2019 08:13:56 +1100
Subject: [PATCH] Allow putpalette for LA and PA

---
 Tests/test_image_putpalette.py |  6 ++++--
 src/PIL/Image.py               | 12 ++++++------
 src/_imaging.c                 |  3 ++-
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/Tests/test_image_putpalette.py b/Tests/test_image_putpalette.py
index 34b585f55..4bac448fd 100644
--- a/Tests/test_image_putpalette.py
+++ b/Tests/test_image_putpalette.py
@@ -14,8 +14,10 @@ class TestImagePutPalette(PillowTestCase):
                 return im.mode, p[:10]
             return im.mode
         self.assertRaises(ValueError, palette, "1")
-        self.assertEqual(palette("L"), ("P", [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
-        self.assertEqual(palette("P"), ("P", [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
+        for mode in ["L", "LA", "P", "PA"]:
+            self.assertEqual(palette(mode),
+                             ("PA" if "A" in mode else "P",
+                              [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
         self.assertRaises(ValueError, palette, "I")
         self.assertRaises(ValueError, palette, "F")
         self.assertRaises(ValueError, palette, "RGB")
diff --git a/src/PIL/Image.py b/src/PIL/Image.py
index ed3719100..dfa526e7a 100644
--- a/src/PIL/Image.py
+++ b/src/PIL/Image.py
@@ -1619,10 +1619,10 @@ class Image(object):
 
     def putpalette(self, data, rawmode="RGB"):
         """
-        Attaches a palette to this image.  The image must be a "P" or
-        "L" image, and the palette sequence must contain 768 integer
-        values, where each group of three values represent the red,
-        green, and blue values for the corresponding pixel
+        Attaches a palette to this image.  The image must be a "P",
+        "PA", "L" or "LA" image, and the palette sequence must contain
+        768 integer values, where each group of three values represent
+        the red, green, and blue values for the corresponding pixel
         index. Instead of an integer sequence, you can use an 8-bit
         string.
 
@@ -1631,7 +1631,7 @@ class Image(object):
         """
         from . import ImagePalette
 
-        if self.mode not in ("L", "P"):
+        if self.mode not in ("L", "LA", "P", "PA"):
             raise ValueError("illegal image mode")
         self.load()
         if isinstance(data, ImagePalette.ImagePalette):
@@ -1643,7 +1643,7 @@ class Image(object):
                 else:
                     data = "".join(chr(x) for x in data)
             palette = ImagePalette.raw(rawmode, data)
-        self.mode = "P"
+        self.mode = "PA" if "A" in self.mode else "P"
         self.palette = palette
         self.palette.mode = "RGB"
         self.load()  # install new palette
diff --git a/src/_imaging.c b/src/_imaging.c
index 614f809bc..037348baa 100644
--- a/src/_imaging.c
+++ b/src/_imaging.c
@@ -1569,7 +1569,8 @@ _putpalette(ImagingObject* self, PyObject* args)
     if (!PyArg_ParseTuple(args, "s"PY_ARG_BYTES_LENGTH, &rawmode, &palette, &palettesize))
         return NULL;
 
-    if (strcmp(self->image->mode, "L") != 0 && strcmp(self->image->mode, "P")) {
+    if (strcmp(self->image->mode, "L") && strcmp(self->image->mode, "LA") &&
+        strcmp(self->image->mode, "P") && strcmp(self->image->mode, "PA")) {
         PyErr_SetString(PyExc_ValueError, wrong_mode);
         return NULL;
     }