From 458e9f64a7c70da6ebd0b53bf9be6cd9d49ae1d7 Mon Sep 17 00:00:00 2001
From: Josh Holmer <jholme.in@gmail.com>
Date: Wed, 19 Jun 2019 15:27:43 -0400
Subject: [PATCH] Fix --strip safe which was broken in 5b1121c9d

---
 src/lib.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/lib.rs b/src/lib.rs
index 226bdf86..70ff06ca 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -863,7 +863,8 @@ fn perform_strip(png: &mut PngData, opts: &Options) {
                 *b"cHRM", *b"gAMA", *b"iCCP", *b"sBIT", *b"sRGB", *b"bKGD", *b"hIST", *b"pHYs",
                 *b"sPLT",
             ];
-            for hdr in &PRESERVED_HEADERS {
+            let keys: Vec<[u8; 4]> = raw.aux_headers.keys().cloned().collect();
+            for hdr in &keys {
                 if !PRESERVED_HEADERS.contains(hdr) {
                     raw.aux_headers.remove(hdr);
                 }