Jeff Smith : gdiplus: Expose GIF background index property only when global color table present.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: ba564e2abaafcb4bcc3428b67bab5e7f9091cb4d
URL:    https://gitlab.winehq.org/wine/wine/-/commit/ba564e2abaafcb4bcc3428b67bab5e7...

Author: Jeff Smith <whydoubt(a)gmail.com>
Date:   Sat Jul 15 14:44:24 2023 -0500

gdiplus: Expose GIF background index property only when global color table present.

---

 dlls/gdiplus/image.c       | 11 +++++++----
 dlls/gdiplus/tests/image.c | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/dlls/gdiplus/image.c b/dlls/gdiplus/image.c
index 4ba6b1efd95..a1ad60ecce3 100644
--- a/dlls/gdiplus/image.c
+++ b/dlls/gdiplus/image.c
@@ -3171,11 +3171,14 @@ static PropertyItem *get_gif_loopcount(IWICMetadataReader *reader)
 
 static PropertyItem *get_gif_background(IWICMetadataReader *reader)
 {
-    PropertyItem *background;
+    PropertyItem *background = NULL;
 
-    background = get_property(reader, &GUID_MetadataFormatLSD, L"BackgroundColorIndex");
-    if (background)
-        background->id = PropertyTagIndexBackground;
+    if (get_bool_property(reader, &GUID_MetadataFormatLSD, L"GlobalColorTableFlag"))
+    {
+        background = get_property(reader, &GUID_MetadataFormatLSD, L"BackgroundColorIndex");
+        if (background)
+            background->id = PropertyTagIndexBackground;
+    }
 
     return background;
 }
diff --git a/dlls/gdiplus/tests/image.c b/dlls/gdiplus/tests/image.c
index 750042bb5c3..4dd39f914b9 100644
--- a/dlls/gdiplus/tests/image.c
+++ b/dlls/gdiplus/tests/image.c
@@ -4838,6 +4838,27 @@ static const BYTE animatedgif[] = {
 0x21,0x01,0x0C,'p','l','a','i','n','t','e','x','t',' ','#','2',0x00,0x3B
 };
 
+static const BYTE gif_2frame_global_pal[] = {
+'G','I','F','8','7','a', 0x01,0x00, 0x01,0x00, 0xa1, 0x02, 0x00,
+0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,
+0x21,0xF9,0x04, 0x00,0x0A,0x00,0x08, 0x00,
+0x2c, 0x00,0x00, 0x00,0x00, 0x01,0x00, 0x01,0x00, 0x01,
+0x02,0x02,0x44,0x01,0x00,
+0x21,0xF9,0x04, 0x00,0x14,0x00,0x08, 0x00,
+0x2c, 0x00,0x00, 0x00,0x00, 0x01,0x00, 0x01,0x00, 0x01,
+0x02,0x02,0x44,0x01,0x00, 0x3b
+};
+
+static const BYTE gif_2frame_no_pal[] = {
+'G','I','F','8','7','a', 0x01,0x00, 0x01,0x00, 0x21, 0x02, 0x00,
+0x21,0xF9,0x04, 0x00,0x0A,0x00,0x08, 0x00,
+0x2c, 0x00,0x00, 0x00,0x00, 0x01,0x00, 0x01,0x00, 0x01,
+0x02,0x02,0x44,0x01,0x00,
+0x21,0xF9,0x04, 0x00,0x14,0x00,0x08, 0x00,
+0x2c, 0x00,0x00, 0x00,0x00, 0x01,0x00, 0x01,0x00, 0x01,
+0x02,0x02,0x44,0x01,0x00, 0x3b
+};
+
 static void test_gif_properties(void)
 {
     static const struct property_test_data animatedgif_props[] =
@@ -4849,6 +4870,18 @@ static void test_gif_properties(void)
         { PropertyTagTypeByte, PropertyTagIndexBackground, 1, { 2 } },
         { PropertyTagTypeByte, PropertyTagIndexTransparent, 1, { 8 } }
     };
+    static const struct property_test_data gif_2frame_global_pal_props[] =
+    {
+        { PropertyTagTypeLong, PropertyTagFrameDelay, 8, { 10,0,0,0,20,0,0,0 } },
+        { PropertyTagTypeShort, PropertyTagLoopCount, 2, { 1,0 } },
+        { PropertyTagTypeByte, PropertyTagGlobalPalette, 12, { 0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c } },
+        { PropertyTagTypeByte, PropertyTagIndexBackground, 1, { 2 } },
+    };
+    static const struct property_test_data gif_2frame_no_pal_props[] =
+    {
+        { PropertyTagTypeLong, PropertyTagFrameDelay, 8, { 10,0,0,0,20,0,0,0 } },
+        { PropertyTagTypeShort, PropertyTagLoopCount, 2, { 1,0 } },
+    };
 
     static const struct test_data {
         const BYTE *image_data;
@@ -4860,6 +4893,8 @@ static void test_gif_properties(void)
     {
 #define giftest(img, prop, frames) { img, sizeof(img), prop, ARRAY_SIZE(prop), frames }
         giftest(animatedgif, animatedgif_props, 2),
+        giftest(gif_2frame_global_pal, gif_2frame_global_pal_props, 2),
+        giftest(gif_2frame_no_pal, gif_2frame_no_pal_props, 2),
 #undef giftest
     };