From 385d9caa8d51c9476b40993ad54bc02ac0457958 Mon Sep 17 00:00:00 2001
From: Andy Fiedler <andy@andyfiedler.com>
Date: Sat, 20 Nov 2021 14:32:04 -0500
Subject: [PATCH] Web backend: call set_index_buffer with size as optional

Size must be passed to setIndexBuffer in Javascript as undefined in order for WebGGPU to use the default size, which is the full buffer size.
---
 wgpu/src/backend/web.rs | 50 ++++++++++++++++++++++++++---------------
 1 file changed, 32 insertions(+), 18 deletions(-)

diff --git a/wgpu/src/backend/web.rs b/wgpu/src/backend/web.rs
index d629361d7b..5e0ed3fb17 100644
--- a/wgpu/src/backend/web.rs
+++ b/wgpu/src/backend/web.rs
@@ -163,16 +163,23 @@ impl crate::RenderInner<Context> for RenderPass {
         offset: wgt::BufferAddress,
         size: Option<wgt::BufferSize>,
     ) {
-        let mapped_size = match size {
-            Some(s) => s.get() as f64,
-            None => 0f64,
+        match size {
+            Some(s) => {
+                self.0.set_index_buffer_with_f64_and_f64(
+                    &buffer.0,
+                    map_index_format(index_format),
+                    offset as f64,
+                    s.get() as f64,
+                );
+            }
+            None => {
+                self.0.set_index_buffer_with_f64(
+                    &buffer.0,
+                    map_index_format(index_format),
+                    offset as f64,
+                );
+            }
         };
-        self.0.set_index_buffer_with_f64_and_f64(
-            &buffer.0,
-            map_index_format(index_format),
-            offset as f64,
-            mapped_size,
-        );
     }
     fn set_vertex_buffer(
         &mut self,
@@ -292,16 +299,23 @@ impl crate::RenderInner<Context> for RenderBundleEncoder {
         offset: wgt::BufferAddress,
         size: Option<wgt::BufferSize>,
     ) {
-        let mapped_size = match size {
-            Some(s) => s.get() as f64,
-            None => 0f64,
+        match size {
+            Some(s) => {
+                self.0.set_index_buffer_with_f64_and_f64(
+                    &buffer.0,
+                    map_index_format(index_format),
+                    offset as f64,
+                    s.get() as f64,
+                );
+            }
+            None => {
+                self.0.set_index_buffer_with_f64(
+                    &buffer.0,
+                    map_index_format(index_format),
+                    offset as f64,
+                );
+            }
         };
-        self.0.set_index_buffer_with_f64_and_f64(
-            &buffer.0,
-            map_index_format(index_format),
-            offset as f64,
-            mapped_size,
-        );
     }
     fn set_vertex_buffer(
         &mut self,