From 06c0932ab4d3f1984d25ef3de886ec9ad94e2897 Mon Sep 17 00:00:00 2001
From: Jaime Passos <lazymyuutsu@gmail.com>
Date: Sat, 10 Oct 2020 14:12:22 -0300
Subject: [PATCH] Only check the tRNS (trans) chunk if the image is still
palettized
---
src/r_picformats.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)
diff --git a/src/r_picformats.c b/src/r_picformats.c
index feec2abf4d..8d7cf37f20 100644
--- a/src/r_picformats.c
+++ b/src/r_picformats.c
@@ -909,20 +909,23 @@ static png_bytep *PNG_Read(
// 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.
- png_get_tRNS(png_ptr, png_info_ptr, &trans, &trans_num, &trans_values);
-
- if (trans && trans_num == 256)
+ if (usepal)
{
- int i;
- for (i = 0; i < trans_num; i++)
+ png_get_tRNS(png_ptr, png_info_ptr, &trans, &trans_num, &trans_values);
+
+ if (trans && trans_num == 256)
{
- // libpng will transform this image into RGB even if
- // the transparent index does not exist in the image,
- // and there is no way around that.
- if (trans[i] < 0xFF)
+ INT32 i;
+ for (i = 0; i < trans_num; i++)
{
- usepal = false;
- break;
+ // libpng will transform this image into RGB even if
+ // the transparent index does not exist in the image,
+ // and there is no way around that.
+ if (trans[i] < 0xFF)
+ {
+ usepal = false;
+ break;
+ }
}
}
}
--
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