From 16d67b1283c214cc898b1dca25318522cf45ecf1 Mon Sep 17 00:00:00 2001
From: Josh Matthews <josh@joshmatthews.net>
Date: Wed, 8 Apr 2020 12:54:12 -0400
Subject: [PATCH] webgl: Avoid GL errors with LineWidth commands.

---
 components/canvas/webgl_thread.rs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/components/canvas/webgl_thread.rs b/components/canvas/webgl_thread.rs
index 8d63b6973f0..28c5bb7240b 100644
--- a/components/canvas/webgl_thread.rs
+++ b/components/canvas/webgl_thread.rs
@@ -1184,7 +1184,13 @@ impl WebGLImpl {
                 gl.enable_vertex_attrib_array(attrib_id)
             },
             WebGLCommand::Hint(name, val) => gl.hint(name, val),
-            WebGLCommand::LineWidth(width) => gl.line_width(width),
+            WebGLCommand::LineWidth(width) => {
+                gl.line_width(width);
+                // In OpenGL Core Profile >3.2, any non-1.0 value will generate INVALID_VALUE.
+                if width != 1.0 {
+                    let _ = gl.get_error();
+                }
+            },
             WebGLCommand::PixelStorei(name, val) => gl.pixel_store_i(name, val),
             WebGLCommand::PolygonOffset(factor, units) => gl.polygon_offset(factor, units),
             WebGLCommand::ReadPixels(rect, format, pixel_type, ref sender) => {