hack to fix completely transparent images

src/gfx/resample_image.cpp

@@ -141,28 +141,10 @@ void resample_and_clip(const Image& img_in, Image& img_out, wxRect rect) {
 
 // ----------------------------------------------------------------------------- : Aspect ratio preserving
 
-// fill an image with 100% transparent, except for the given rectangle
-void fill_transparent(Image& img, int dx, int dy, int w, int h) {
+// fill an image with 100% transparent
+void fill_transparent(Image& img) {
 	if (!img.HasAlpha()) img.InitAlpha();
 	memset(img.GetAlpha(), 0, img.GetWidth() * img.GetHeight());
-	/*/?
-	int iw = img.GetWidth(), ih = img.GetHeight();
-	Byte* data = img.GetAlpha();
-	// fill
-	int y = 0;
-	for (; y < dy ; ++y) {
-		for (int x = 0 ; x < iw ; ++x) *data++ = 0;
-	}
-	for (; y < dy + h ; ++y) {
-		int x = 0;
-		for (; x < dx     ; ++x) *data++ = 0;
-		for (; x < dx + w ; ++x) *data++ = 255;
-		for (; x < iw     ; ++x) *data++ = 0;
-	}
-	for (; y < ih ; ++y) {
-		for (int x = 0 ; x < iw ; ++x) *data++ = 0;
-	}
-	*/
 }
 
 void resample_preserve_aspect(const Image& img_in, Image& img_out) {
@@ -175,10 +157,11 @@ void resample_preserve_aspect(const Image& img_in, Image& img_out) {
 	int dx = (img_out.GetWidth()  - rwidth)  / 2;
 	int dy = (img_out.GetHeight() - rheight) / 2;
 	// transparent background
-	fill_transparent(img_out, dx, dy, rwidth, rheight);
+	fill_transparent(img_out);
 	// resample
 	int offset_out = dx + img_out.GetWidth() * dy;
 	Image img_temp(rwidth, img_in.GetHeight(), false);
+	img_temp.InitAlpha();
 	resample_pass(img_in,   img_temp, 0, 0,          img_in.GetWidth(),  1,                   rwidth,  1,                  img_in.GetHeight(), img_in.GetWidth(), img_temp.GetWidth());
 	resample_pass(img_temp, img_out,  0, offset_out, img_in.GetHeight(), img_temp.GetWidth(), rheight, img_out.GetWidth(), rwidth,             1,                 1);
 }

src/gui/value/choice.cpp

@@ -51,6 +51,27 @@ void ChoiceThumbnailRequest::store(const Image& img) {
 		il->Add(wxBitmap(16,16),*wxBLACK);
 	}
 	if (img.Ok()) {
+		#ifdef __WXMSW__
+			// for some reason windows doesn't like completely transparent images if they do not have a mask
+			// HACK:
+			if (img.GetWidth() == 16 && img.GetHeight() == 16) {
+				// is the image empty?
+				bool empty = true;
+				int* b = (int*)img.GetAlpha();
+				int* e = b + 16*16/sizeof(int);
+				while (b != e) {
+					if (*b++) {
+						empty = false;
+						break;
+					}
+				}
+				// if so, use a mask instead
+				if (empty) {
+					const_cast<Image&>(img).ConvertAlphaToMask();
+				}
+			}
+			// Hack ends here
+		#endif
 		if (id == il->GetImageCount()) {
 			il->Add(img);
 		} else {