Correctly read JPEG compressed BLP images

Tests/test_file_blp.py

@@ -5,6 +5,11 @@
 from .helper import assert_image_equal_tofile
 
 
+def test_load_blp1():
+    with Image.open("Tests/images/blp/blp1_jpeg.blp") as im:
+        assert_image_equal_tofile(im, "Tests/images/blp/blp1_jpeg.png")
+
+
 def test_load_blp2_raw():
     with Image.open("Tests/images/blp/blp2_raw.blp") as im:
         assert_image_equal_tofile(im, "Tests/images/blp/blp2_raw.png")

src/PIL/BlpImagePlugin.py

@@ -357,9 +357,9 @@ def _decode_jpeg_stream(self):
         data = BytesIO(data)
         image = JpegImageFile(data)
         Image._decompression_bomb_check(image.size)
-        self.tile = image.tile  # :/
-        self.fd = image.fp
-        self.mode = image.mode
+        image.mode = "RGB"
+        image.tile = [("jpeg", (0, 0) + self.size, 0, ("BGRX", ""))]
+        self.set_as_raw(image.tobytes())
 
 
 class BLP2Decoder(_BLPBaseDecoder):