From 74f514ca6b1a4f3b90a8ce94306aff08bbd4eb12 Mon Sep 17 00:00:00 2001
From: Erich Gubler <erichdongubler@gmail.com>
Date: Thu, 21 Mar 2024 16:09:29 -0400
Subject: [PATCH] fix(gles): don't depend on BG{,L} entry order

This isn't guaranteed by `wgpu-core`; we should try to match by binding
slot index instead.
---
 CHANGELOG.md                |  1 +
 wgpu-hal/src/gles/device.rs | 17 ++++++++++++++---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c443ecd89c..ca0b07415a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -157,6 +157,7 @@ Bottom level categories:
 - Fixes for being able to use an OpenGL 4.1 core context provided by macOS with wgpu. By @bes in [#5331](https://github.com/gfx-rs/wgpu/pull/5331).
 - Don't create a program for shader-clearing if that workaround isn't required. By @Dinnerbone in [#5348](https://github.com/gfx-rs/wgpu/pull/5348).
 - Fix crash when holding multiple devices on wayland/surfaceless. By @ashdnazg in [#5351](https://github.com/gfx-rs/wgpu/pull/5351).
+- Don't depend on bind group and bind group layout entry order in HAL. This caused incorrect severely incorrect command execution and, in some cases, crashes. By @ErichDonGubler in [#5421](https://github.com/gfx-rs/wgpu/pull/5421).
 
 #### Vulkan
 
diff --git a/wgpu-hal/src/gles/device.rs b/wgpu-hal/src/gles/device.rs
index 8cc3129d65..50c07f3ff0 100644
--- a/wgpu-hal/src/gles/device.rs
+++ b/wgpu-hal/src/gles/device.rs
@@ -1125,8 +1125,10 @@ impl crate::Device for super::Device {
                 !0;
                 bg_layout
                     .entries
-                    .last()
-                    .map_or(0, |b| b.binding as usize + 1)
+                    .iter()
+                    .map(|b| b.binding)
+                    .max()
+                    .map_or(0, |idx| idx as usize + 1)
             ]
             .into_boxed_slice();
 
@@ -1179,7 +1181,16 @@ impl crate::Device for super::Device {
     ) -> Result<super::BindGroup, crate::DeviceError> {
         let mut contents = Vec::new();
 
-        for (entry, layout) in desc.entries.iter().zip(desc.layout.entries.iter()) {
+        let layout_and_entry_iter = desc.entries.iter().map(|entry| {
+            let layout = desc
+                .layout
+                .entries
+                .iter()
+                .find(|layout_entry| layout_entry.binding == entry.binding)
+                .expect("internal error: no layout entry found with binding slot");
+            (entry, layout)
+        });
+        for (entry, layout) in layout_and_entry_iter {
             let binding = match layout.ty {
                 wgt::BindingType::Buffer { .. } => {
                     let bb = &desc.buffers[entry.resource_index as usize];