[PATCH 0/3] MR3344: windowscodecs: support GIF with no color table

[Jeffrey Smith (＠whydoubt)]

Decoding a GIF with no color table currently crashes on Wine.
Windows supports such files, and the GIF spec explicitly allows it.

[PATCH 1/3] windowscodecs/tests: Expand GIF palette tests.

[Jeff Smith]

From: Jeff Smith

---
 dlls/windowscodecs/tests/gifformat.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/dlls/windowscodecs/tests/gifformat.c b/dlls/windowscodecs/tests/gifformat.c
index 8488f486a11..3f60d35a70f 100644
--- a/dlls/windowscodecs/tests/gifformat.c
+++ b/dlls/windowscodecs/tests/gifformat.c
@@ -130,7 +130,7 @@ static void test_global_gif_palette(void)
     IWICBitmapFrameDecode *frame;
     IWICPalette *palette;
     GUID format;
-    UINT count, ret;
+    UINT count, ret, i;
     WICColor color[256];

decoder = create_decoder(gif_global_palette, sizeof(gif_global_palette));
@@ -147,6 +147,8 @@ static void test_global_gif_palette(void)
     ok(hr == S_OK, "GetColorCount error %#lx\n", hr);
     ok(count == 4, "expected 4, got %u\n", count);

+    for (i = 0; i < 256; i++)
+        color[i] = 0xdeadbeef;
     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);
@@ -154,6 +156,8 @@ static void test_global_gif_palette(void)
     ok(color[1] == 0x00040506, "expected 0x00040506, got %#x\n", color[1]);
     ok(color[2] == 0xff070809, "expected 0xff070809, got %#x\n", color[2]);
     ok(color[3] == 0xff0a0b0c, "expected 0xff0a0b0c, got %#x\n", color[3]);
+    for (i = 4; i < 256; i++)
+        ok(color[i] == 0xdeadbeef, "expected 0xdeadbeef, got %#x\n", color[i]);

/* frame palette */
     hr = IWICBitmapDecoder_GetFrame(decoder, 0, &frame);
@@ -171,6 +175,8 @@ static void test_global_gif_palette(void)
     ok(hr == S_OK, "GetColorCount error %#lx\n", hr);
     ok(count == 4, "expected 4, got %u\n", count);

+    for (i = 0; i < 256; i++)
+        color[i] = 0xdeadbeef;
     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);
@@ -178,6 +184,8 @@ static void test_global_gif_palette(void)
     ok(color[1] == 0x00040506, "expected 0x00040506, got %#x\n", color[1]);
     ok(color[2] == 0xff070809, "expected 0xff070809, got %#x\n", color[2]);
     ok(color[3] == 0xff0a0b0c, "expected 0xff0a0b0c, got %#x\n", color[3]);
+    for (i = 4; i < 256; i++)
+        ok(color[i] == 0xdeadbeef, "expected 0xdeadbeef, got %#x\n", color[i]);

IWICPalette_Release(palette);
     IWICBitmapFrameDecode_Release(frame);
@@ -320,12 +328,13 @@ static void test_local_gif_palette(void)
         ok(hr == S_OK, "GetColorCount error %#lx\n", hr);
         ok(count == 256, "expected 256, got %u\n", count);

+        for (i = 0; i < 256; i++)
+            color[i] = 0xdeadbeef;
         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]);
-
         for (i = 2; i < 256; i++)
             ok(color[i] == 0xff000000, "expected 0xff000000, got %#x\n", color[i]);
     }
@@ -351,6 +360,8 @@ static void test_local_gif_palette(void)
     ok(hr == S_OK, "GetType error %#lx\n", hr);
     ok(type == WICBitmapPaletteTypeCustom, "expected WICBitmapPaletteTypeCustom, got %#x\n", type);

+    for (i = 0; i < 256; i++)
+        color[i] = 0xdeadbeef;
     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);
@@ -358,6 +369,8 @@ static void test_local_gif_palette(void)
     ok(color[1] == 0x00040506, "expected 0x00040506, got %#x\n", color[1]);
     ok(color[2] == 0xff070809, "expected 0xff070809, got %#x\n", color[2]);
     ok(color[3] == 0xff0a0b0c, "expected 0xff0a0b0c, got %#x\n", color[3]);
+    for (i = 4; i < 256; i++)
+        ok(color[i] == 0xdeadbeef, "expected 0xdeadbeef, got %#x\n", color[i]);

IWICPalette_Release(palette);
     IWICBitmapFrameDecode_Release(frame);

[PATCH 2/3] windowscodecs: Factor out common GIF palette copying logic.

[Jeff Smith]

From: Jeff Smith

---
 dlls/windowscodecs/gifformat.c | 92 +++++++++++++++-------------------
 1 file changed, 40 insertions(+), 52 deletions(-)

diff --git a/dlls/windowscodecs/gifformat.c b/dlls/windowscodecs/gifformat.c
index f0048d12da9..c7e0f83c856 100644
--- a/dlls/windowscodecs/gifformat.c
+++ b/dlls/windowscodecs/gifformat.c
@@ -701,14 +701,49 @@ static HRESULT WINAPI GifFrameDecode_GetResolution(IWICBitmapFrameDecode *iface,
     return S_OK;
 }

+static void copy_palette(ColorMapObject *cm, Extensions *extensions, int count, WICColor *colors)
+{
+    int i;
+
+    if (cm)
+    {
+        for (i = 0; i < count; i++)
+        {
+            colors[i] = 0xff000000 | /* alpha */
+                        cm->Colors[i].Red << 16 |
+                        cm->Colors[i].Green << 8 |
+                        cm->Colors[i].Blue;
+        }
+    }
+    else
+    {
+        colors[0] = 0xff000000;
+        colors[1] = 0xffffffff;
+        for (i = 2; i < count; i++)
+            colors[i] = 0xff000000;
+    }
+
+    /* look for the transparent color extension */
+    for (i = 0; i < extensions->ExtensionBlockCount; i++)
+    {
+        ExtensionBlock *eb = extensions->ExtensionBlocks + i;
+        if (eb->Function == GRAPHICS_EXT_FUNC_CODE &&
+            eb->ByteCount == 8 && eb->Bytes[3] & 1)
+        {
+            int trans = (unsigned char)eb->Bytes[6];
+            colors[trans] &= 0xffffff; /* set alpha to 0 */
+            break;
+        }
+    }
+}
+
 static HRESULT WINAPI GifFrameDecode_CopyPalette(IWICBitmapFrameDecode *iface,
     IWICPalette *pIPalette)
 {
     GifFrameDecode *This = impl_from_IWICBitmapFrameDecode(iface);
     WICColor colors[256];
     ColorMapObject *cm = This->frame->ImageDesc.ColorMap;
-    int i, trans;
-    ExtensionBlock *eb;
+
     TRACE("(%p,%p)\n", iface, pIPalette);

if (!cm) cm = This->parent->gif->SColorMap;
@@ -719,24 +754,7 @@ static HRESULT WINAPI GifFrameDecode_CopyPalette(IWICBitmapFrameDecode *iface,
         return E_FAIL;
     }

-    for (i = 0; i < cm->ColorCount; i++) {
-        colors[i] = 0xff000000| /* alpha */
-                    cm->Colors[i].Red << 16|
-                    cm->Colors[i].Green << 8|
-                    cm->Colors[i].Blue;
-    }
-
-    /* look for the transparent color extension */
-    for (i = 0; i < This->frame->Extensions.ExtensionBlockCount; ++i) {
-	eb = This->frame->Extensions.ExtensionBlocks + i;
-	if (eb->Function == GRAPHICS_EXT_FUNC_CODE && eb->ByteCount == 8) {
-	    if (eb->Bytes[3] & 1) {
-	        trans = (unsigned char)eb->Bytes[6];
-	        colors[trans] &= 0xffffff; /* set alpha to 0 */
-	        break;
-	    }
-	}
-    }
+    copy_palette(cm, &This->frame->Extensions, count, cm->ColorCount);

return IWICPalette_InitializeCustom(pIPalette, colors, cm->ColorCount);
 }
@@ -1170,8 +1188,7 @@ static HRESULT WINAPI GifDecoder_CopyPalette(IWICBitmapDecoder *iface, IWICPalet
     GifDecoder *This = impl_from_IWICBitmapDecoder(iface);
     WICColor colors[256];
     ColorMapObject *cm;
-    int i, trans, count;
-    ExtensionBlock *eb;
+    int count;

TRACE("(%p,%p)\n", iface, palette);

@@ -1187,41 +1204,12 @@ static HRESULT WINAPI GifDecoder_CopyPalette(IWICBitmapDecoder *iface, IWICPalet
             return E_FAIL;
         }

-        for (i = 0; i < cm->ColorCount; i++)
-        {
-            colors[i] = 0xff000000 | /* alpha */
-                        cm->Colors[i].Red << 16 |
-                        cm->Colors[i].Green << 8 |
-                        cm->Colors[i].Blue;
-        }
-
         count = cm->ColorCount;
     }
     else
-    {
-        colors[0] = 0xff000000;
-        colors[1] = 0xffffffff;
-
-        for (i = 2; i < 256; i++)
-            colors[i] = 0xff000000;
-
         count = 256;
-    }

-    /* look for the transparent color extension */
-    for (i = 0; i < This->gif->SavedImages[This->current_frame].Extensions.ExtensionBlockCount; i++)
-    {
-        eb = This->gif->SavedImages[This->current_frame].Extensions.ExtensionBlocks + i;
-        if (eb->Function == GRAPHICS_EXT_FUNC_CODE && eb->ByteCount == 8)
-        {
-            if (eb->Bytes[3] & 1)
-            {
-                trans = (unsigned char)eb->Bytes[6];
-                colors[trans] &= 0xffffff; /* set alpha to 0 */
-                break;
-            }
-        }
-    }
+    copy_palette(cm, &This->gif->SavedImages[This->current_frame].Extensions, count, colors);

return IWICPalette_InitializeCustom(palette, colors, count);
 }

[PATCH 3/3] windowscodecs: Allow GIF with no color table.

[Jeff Smith]

From: Jeff Smith

---
 dlls/windowscodecs/gifformat.c       | 32 ++++++------
 dlls/windowscodecs/tests/gifformat.c | 78 ++++++++++++++++++++++++++++
 dlls/windowscodecs/ungif.c           |  1 +
 dlls/windowscodecs/ungif.h           |  1 +
 4 files changed, 97 insertions(+), 15 deletions(-)

diff --git a/dlls/windowscodecs/gifformat.c b/dlls/windowscodecs/gifformat.c
index c7e0f83c856..152c51eac76 100644
--- a/dlls/windowscodecs/gifformat.c
+++ b/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, count, cm->ColorCount);
+    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,
@@ -1196,18 +1203,13 @@ static HRESULT WINAPI GifDecoder_CopyPalette(IWICBitmapDecoder *iface, IWICPalet
         return WINCODEC_ERR_WRONGSTATE;

cm = This->gif->SColorMap;
-    if (cm)
-    {
-        if (cm->ColorCount > 256)
-        {
-            ERR("GIF contains invalid number of colors: %d\n", cm->ColorCount);
-            return E_FAIL;
-        }
+    count = This->gif->SColorTableSize;

-        count = cm->ColorCount;
+    if (count > 256)
+    {
+        ERR("GIF contains invalid number of colors: %d\n", count);
+        return E_FAIL;
     }
-    else
-        count = 256;

copy_palette(cm, &This->gif->SavedImages[This->current_frame].Extensions, count, colors);

diff --git a/dlls/windowscodecs/tests/gifformat.c b/dlls/windowscodecs/tests/gifformat.c
index 3f60d35a70f..4185d306e46 100644
--- a/dlls/windowscodecs/tests/gifformat.c
+++ b/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 \
@@ -377,6 +384,75 @@ 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, i;
+    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);
+
+    for (i = 0; i < 256; i++)
+        color[i] = 0xdeadbeef;
+    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]);
+    for (i = 4; i < 256; i++)
+        ok(color[i] == 0xdeadbeef, "expected 0xdeadbeef, got %#x\n", color[i]);
+
+    /* 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);
+
+    for (i = 0; i < 256; i++)
+        color[i] = 0xdeadbeef;
+    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]);
+    for (i = 4; i < 256; i++)
+        ok(color[i] == 0xdeadbeef, "expected 0xdeadbeef, got %#x\n", color[i]);
+
+    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};
@@ -590,6 +666,7 @@ 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();

@@ -603,6 +680,7 @@ 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();

diff --git a/dlls/windowscodecs/ungif.c b/dlls/windowscodecs/ungif.c
index 0f5ed6e25d5..1fb16e52f15 100644
--- a/dlls/windowscodecs/ungif.c
+++ b/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? */
diff --git a/dlls/windowscodecs/ungif.h b/dlls/windowscodecs/ungif.h
index ae8269226df..f61a7eb1e16 100644
--- a/dlls/windowscodecs/ungif.h
+++ b/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. */