From b654c84eed6cb3d5f172da57c68c92c6565a6cb7 Mon Sep 17 00:00:00 2001
From: AlexTMjugador <AlexTMjugador@users.noreply.github.com>
Date: Fri, 23 Oct 2020 15:23:10 +0200
Subject: [PATCH] Make cloudflare-zlib dependency optional

Although the Cloudflare fork of zlib may introduce performance
improvements, there are issues building it with MinGW toolchains on
Windows, as evidenced by this StackOverflow question: https://stackoverflow.com/questions/61170244/gcc-exe-fail-when-building-cloudflare-zlib-sys-rs

However, it is not always possible to switch to the MSVC toolchain on
Windows, because that may break other native C libraries which have
trouble with MSVC instead, and just compiling to a 32-bit target can get
pretty messy too.

I've opened an issue to get this error fixed upstream, in the
cloudflare-zlib-sys crate, but it was not fixed there yet.

Therefore, make the Cloudflare zlib dependency optional, so users will
have to explicitly opt in for it. As a side bonus, these changes also
remove the restriction of Cloudflare zlib only being available on x64
and Aarch64 platforms.
---
 Cargo.toml         | 3 ++-
 src/deflate/mod.rs | 6 +++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 57111fae..233a2afd 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -59,7 +59,8 @@ default-features = false
 features = ["png"]
 version = "0.23"
 
-[target.'cfg(any(target_arch = "x86_64", target_arch = "aarch64"))'.dependencies.cloudflare-zlib]
+[dependencies.cloudflare-zlib]
+optional = true
 features = ["arm-always"]
 version = "^0.2.2"
 
diff --git a/src/deflate/mod.rs b/src/deflate/mod.rs
index 69879901..017c41d2 100644
--- a/src/deflate/mod.rs
+++ b/src/deflate/mod.rs
@@ -12,10 +12,10 @@ mod deflater;
 #[cfg(feature = "libdeflater")]
 pub use deflater::deflate as libdeflater_deflate;
 
-#[cfg(any(target_arch = "x86_64", target_arch = "aarch64"))]
+#[cfg(feature = "cloudflare-zlib")]
 pub mod cfzlib;
 
-#[cfg(not(any(target_arch = "x86_64", target_arch = "aarch64")))]
+#[cfg(not(feature = "cloudflare-zlib"))]
 pub mod cfzlib {
     pub fn is_supported() -> bool {
         return false;
@@ -38,7 +38,7 @@ pub fn deflate(
     max_size: &AtomicMin,
     deadline: &Deadline,
 ) -> PngResult<Vec<u8>> {
-    #[cfg(any(target_arch = "x86_64", target_arch = "aarch64"))]
+    #[cfg(feature = "cloudflare-zlib")]
     {
         if cfzlib::is_supported() {
             return cfzlib::cfzlib_deflate(data, zc, zs, zw, max_size, deadline);