Only check the tRNS (trans) chunk if the image is still palettized

This commit is contained in:
Jaime Passos 2020-10-10 14:12:22 -03:00
parent 4d847f4223
commit 06c0932ab4

View file

@ -909,11 +909,13 @@ static png_bytep *PNG_Read(
// If any of the tRNS colors have an alpha lower than 0xFF, and that // If any of the tRNS colors have an alpha lower than 0xFF, and that
// color is present on the image, the palette flag is disabled. // color is present on the image, the palette flag is disabled.
if (usepal)
{
png_get_tRNS(png_ptr, png_info_ptr, &trans, &trans_num, &trans_values); png_get_tRNS(png_ptr, png_info_ptr, &trans, &trans_num, &trans_values);
if (trans && trans_num == 256) if (trans && trans_num == 256)
{ {
int i; INT32 i;
for (i = 0; i < trans_num; i++) for (i = 0; i < trans_num; i++)
{ {
// libpng will transform this image into RGB even if // libpng will transform this image into RGB even if
@ -926,6 +928,7 @@ static png_bytep *PNG_Read(
} }
} }
} }
}
if (usepal) if (usepal)
*use_palette = true; *use_palette = true;