From 9bd574058e46b192ae8ec631991e521aa8655e4f Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Wed, 26 Jul 2023 19:13:56 +1000
Subject: [PATCH] Support BGR;15, BGR;16 and BGR;24 in putdata

---
 Tests/test_image_putdata.py |  9 +++++++
 src/_imaging.c              | 49 ++++++++++++++++++++++++++++---------
 2 files changed, 46 insertions(+), 12 deletions(-)

diff --git a/Tests/test_image_putdata.py b/Tests/test_image_putdata.py
index 0e6293349bc..4e40aec7465 100644
--- a/Tests/test_image_putdata.py
+++ b/Tests/test_image_putdata.py
@@ -76,6 +76,15 @@ def test_mode_F():
     assert list(im.getdata()) == target
 
 
+@pytest.mark.parametrize("mode", ("BGR;15", "BGR;16", "BGR;24"))
+def test_mode_BGR(mode):
+    data = [(16, 32, 49), (32, 32, 98)]
+    im = Image.new(mode, (1, 2))
+    im.putdata(data)
+
+    assert list(im.getdata()) == data
+
+
 def test_array_B():
     # shouldn't segfault
     # see https://github.com/python-pillow/Pillow/issues/1008
diff --git a/src/_imaging.c b/src/_imaging.c
index c331669a74a..95e1f4c0896 100644
--- a/src/_imaging.c
+++ b/src/_imaging.c
@@ -1573,21 +1573,46 @@ if (PySequence_Check(op)) { \
                 PyErr_SetString(PyExc_TypeError, must_be_sequence);
                 return NULL;
             }
-            int endian = strncmp(image->mode, "I;16", 4) == 0 ? (strcmp(image->mode, "I;16B") == 0 ? 2 : 1) : 0;
             double value;
-            for (i = x = y = 0; i < n; i++) {
-                set_value_to_item(seq, i);
-                if (scale != 1.0 || offset != 0.0) {
-                    value = value * scale + offset;
+            if (image->bands == 1) {
+                int bigendian;
+                if (image->type == IMAGING_TYPE_SPECIAL) {
+                    // I;16*
+                    bigendian = strcmp(image->mode, "I;16B") == 0;
                 }
-                if (endian == 0) {
-                    image->image8[y][x] = (UINT8)CLIP8(value);
-                } else {
-                    image->image8[y][x * 2 + (endian == 2 ? 1 : 0)] = CLIP8((int)value % 256);
-                    image->image8[y][x * 2 + (endian == 2 ? 0 : 1)] = CLIP8((int)value >> 8);
+                for (i = x = y = 0; i < n; i++) {
+                    set_value_to_item(seq, i);
+                    if (scale != 1.0 || offset != 0.0) {
+                        value = value * scale + offset;
+                    }
+                    if (image->type == IMAGING_TYPE_SPECIAL) {
+                        image->image8[y][x * 2 + (bigendian ? 1 : 0)] = CLIP8((int)value % 256);
+                        image->image8[y][x * 2 + (bigendian ? 0 : 1)] = CLIP8((int)value >> 8);
+                    } else {
+                        image->image8[y][x] = (UINT8)CLIP8(value);
+                    }
+                    if (++x >= (int)image->xsize) {
+                        x = 0, y++;
+                    }
                 }
-                if (++x >= (int)image->xsize) {
-                    x = 0, y++;
+            } else {
+                // BGR;*
+                int b;
+                for (i = x = y = 0; i < n; i++) {
+                    char ink[4];
+
+                    op = PySequence_Fast_GET_ITEM(seq, i);
+                    if (!op || !getink(op, image, ink)) {
+                        Py_DECREF(seq);
+                        return NULL;
+                    }
+                    /* FIXME: what about scale and offset? */
+                    for (b = 0; b < image->pixelsize; b++) {
+                        image->image8[y][x * image->pixelsize + b] = ink[b];
+                    }
+                    if (++x >= (int)image->xsize) {
+                        x = 0, y++;
+                    }
                 }
             }
             PyErr_Clear(); /* Avoid weird exceptions */