From d240c612f18cb4c8b2eb7487d675cbed5346adb6 Mon Sep 17 00:00:00 2001
From: Felix Hanau <felix@cloudflare.com>
Date: Mon, 22 Jul 2019 13:30:27 +0100
Subject: [PATCH] Also sort when reducing to palette

---
 src/reduction/mod.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/reduction/mod.rs b/src/reduction/mod.rs
index c8fd94d9..0fa1476f 100644
--- a/src/reduction/mod.rs
+++ b/src/reduction/mod.rs
@@ -226,6 +226,14 @@ pub fn reduce_color_type(png: &PngImage) -> Option<PngImage> {
         }
     }
 
+    //Make sure that palette gets sorted. Ideally, this should be done within reduced_color_to_palette.
+    if should_reduce_bit_depth && reduced.ihdr.color_type == ColorType::Indexed {
+        if let Some(r) = reduced_palette(&reduced) {
+            reduced = Cow::Owned(r);
+            should_reduce_bit_depth = true;
+        }
+    }
+
     if should_reduce_bit_depth {
         // Some conversions will allow us to perform bit depth reduction that
         // wasn't possible before