windowscodecs: Allow GIF with no color table.

dlls/windowscodecs/gifformat.c

@@ -743,20 +743,27 @@ static HRESULT WINAPI GifFrameDecode_CopyPalette(IWICBitmapFrameDecode *iface,
     GifFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
     WICColor colors[256];
     ColorMapObject *cm = This->frame->ImageDesc.ColorMap;
+    int count;
 
     TRACE("(%p,%p)\n", iface, pIPalette);
 
-    if (!cm) cm = This->parent->gif->SColorMap;
+    if (cm)
+        count = cm->ColorCount;
+    else
+    {
+        cm = This->parent->gif->SColorMap;
+        count = This->parent->gif->SColorTableSize;
+    }
 
-    if (cm->ColorCount > 256)
+    if (count > 256)
     {
-        ERR("GIF contains %i colors???\n", cm->ColorCount);
+        ERR("GIF contains %i colors???\n", count);
         return E_FAIL;
     }
 
-    copy_palette(cm, &This->frame->Extensions, cm->ColorCount, colors);
+    copy_palette(cm, &This->frame->Extensions, count, colors);
 
-    return IWICPalette_InitializeCustom(pIPalette, colors, cm->ColorCount);
+    return IWICPalette_InitializeCustom(pIPalette, colors, count);
 }
 
 static HRESULT copy_interlaced_pixels(const BYTE *srcbuffer,
@@ -1196,19 +1203,14 @@ static HRESULT WINAPI GifDecoder_CopyPalette(IWICBitmapDecoder *iface, IWICPalet
         return WINCODEC_ERR_WRONGSTATE;
 
     cm = This->gif->SColorMap;
-    if (cm)
-    {
-        if (cm->ColorCount > 256)
+    count = This->gif->SColorTableSize;
+
+    if (count > 256)
     {
-            ERR("GIF contains invalid number of colors: %d\n", cm->ColorCount);
+        ERR("GIF contains invalid number of colors: %d\n", count);
         return E_FAIL;
     }
 
-        count = cm->ColorCount;
-    }
-    else
-        count = 256;
-
     copy_palette(cm, &This->gif->SavedImages[This->current_frame].Extensions, count, colors);
 
     return IWICPalette_InitializeCustom(palette, colors, count);

dlls/windowscodecs/tests/gifformat.c

@@ -57,6 +57,13 @@ static const char gif_local_palette[] = {
 0x02,0x02,0x44,0x01,0x00,0x3b
 };
 
+static const char gif_no_palette[] = {
+/* LSD */'G','I','F','8','7','a',0x01,0x00,0x01,0x00,0x21,0x02,0x00,
+/* GCE */0x21,0xf9,0x04,0x01,0x05,0x00,0x01,0x00, /* index 1 */
+/* IMD */0x2c,0x00,0x00,0x00,0x00,0x01,0x00,0x01,0x00,0x00,
+0x02,0x02,0x44,0x01,0x00,0x3b
+};
+
 /* Generated with ImageMagick:
  * convert -delay 100 -size 2x2 xc:red \
  *     -dispose none -page +0+0 -size 2x1 xc:white \
@@ -364,6 +371,67 @@ static void test_local_gif_palette(void)
     IWICBitmapDecoder_Release(decoder);
 }
 
+static void test_no_gif_palette(void)
+{
+    HRESULT hr;
+    IWICBitmapDecoder *decoder;
+    IWICBitmapFrameDecode *frame;
+    IWICPalette *palette;
+    GUID format;
+    UINT count, ret;
+    WICColor color[256];
+
+    decoder = create_decoder(gif_no_palette, sizeof(gif_no_palette));
+    ok(decoder != 0, "Failed to load GIF image data\n");
+
+    hr = IWICImagingFactory_CreatePalette(factory, &palette);
+    ok(hr == S_OK, "CreatePalette error %#lx\n", hr);
+
+    /* global palette */
+    hr = IWICBitmapDecoder_CopyPalette(decoder, palette);
+    ok(hr == S_OK, "CopyPalette error %#lx\n", hr);
+
+    hr = IWICPalette_GetColorCount(palette, &count);
+    ok(hr == S_OK, "GetColorCount error %#lx\n", hr);
+    ok(count == 4, "expected 4, got %u\n", count);
+
+    hr = IWICPalette_GetColors(palette, count, color, &ret);
+    ok(hr == S_OK, "GetColors error %#lx\n", hr);
+    ok(ret == count, "expected %u, got %u\n", count, ret);
+    ok(color[0] == 0xff000000, "expected 0xff000000, got %#x\n", color[0]);
+    ok(color[1] == 0x00ffffff, "expected 0x00ffffff, got %#x\n", color[1]);
+    ok(color[2] == 0xff000000, "expected 0xff000000, got %#x\n", color[2]);
+    ok(color[3] == 0xff000000, "expected 0xff000000, got %#x\n", color[3]);
+
+    /* frame palette */
+    hr = IWICBitmapDecoder_GetFrame(decoder, 0, &frame);
+    ok(hr == S_OK, "GetFrame error %#lx\n", hr);
+
+    hr = IWICBitmapFrameDecode_GetPixelFormat(frame, &format);
+    ok(hr == S_OK, "GetPixelFormat error %#lx\n", hr);
+    ok(IsEqualGUID(&format, &GUID_WICPixelFormat8bppIndexed),
+       "wrong pixel format %s\n", wine_dbgstr_guid(&format));
+
+    hr = IWICBitmapFrameDecode_CopyPalette(frame, palette);
+    ok(hr == S_OK, "CopyPalette error %#lx\n", hr);
+
+    hr = IWICPalette_GetColorCount(palette, &count);
+    ok(hr == S_OK, "GetColorCount error %#lx\n", hr);
+    ok(count == 4, "expected 4, got %u\n", count);
+
+    hr = IWICPalette_GetColors(palette, count, color, &ret);
+    ok(hr == S_OK, "GetColors error %#lx\n", hr);
+    ok(ret == count, "expected %u, got %u\n", count, ret);
+    ok(color[0] == 0xff000000, "expected 0xff000000, got %#x\n", color[0]);
+    ok(color[1] == 0x00ffffff, "expected 0x00ffffff, got %#x\n", color[1]);
+    ok(color[2] == 0xff000000, "expected 0xff000000, got %#x\n", color[2]);
+    ok(color[3] == 0xff000000, "expected 0xff000000, got %#x\n", color[3]);
+
+    IWICPalette_Release(palette);
+    IWICBitmapFrameDecode_Release(frame);
+    IWICBitmapDecoder_Release(decoder);
+}
+
 static void test_gif_frame_sizes(void)
 {
     static const BYTE frame0[] = {0, 1, 0xfe, 0xfe, 2, 3, 0xfe, 0xfe};
@@ -577,6 +645,7 @@ START_TEST(gifformat)
     test_global_gif_palette();
     test_global_gif_palette_2frames();
     test_local_gif_palette();
+    test_no_gif_palette();
     test_gif_frame_sizes();
     test_gif_notrailer();
 
@@ -590,6 +659,7 @@ START_TEST(gifformat)
     test_global_gif_palette();
     test_global_gif_palette_2frames();
     test_local_gif_palette();
+    test_no_gif_palette();
     test_gif_frame_sizes();
     test_truncated_gif();
 

dlls/windowscodecs/ungif.c

@@ -320,6 +320,7 @@ DGifGetScreenDesc(GifFileType * GifFile) {
     GifFile->SColorResolution = (((Buf[0] & 0x70) + 1) >> 4) + 1;
     SortFlag = (Buf[0] & 0x08) != 0;
     BitsPerPixel = (Buf[0] & 0x07) + 1;
+    GifFile->SColorTableSize = 1 << BitsPerPixel;
     GifFile->SBackGroundColor = Buf[1];
     GifFile->SAspectRatio = Buf[2];
     if (Buf[0] & 0x80) {    /* Do we have global color map? */

dlls/windowscodecs/ungif.h

@@ -114,6 +114,7 @@ typedef struct {
 typedef struct GifFileType {
     GifWord SWidth, SHeight,        /* Screen dimensions. */
       SColorResolution,         /* How many colors can we generate? */
+      SColorTableSize,          /* Calculated color table size, even if not present */
       SBackGroundColor,         /* I hope you understand this one... */
       SAspectRatio;             /* Pixel aspect ratio, in 1/64 units, starting at 1:4. */
     ColorMapObject *SColorMap;  /* NULL if not exists. */