From 12a96caaf19e39611d8f1fff96d9925ca9e134f8 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Tue, 9 Aug 2016 23:23:42 -0700
Subject: [PATCH] webgl: Validate that depthRange near <= far.

Fixes a subtest of webgl-specific.html.
---
 components/script/dom/webglrenderingcontext.rs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/components/script/dom/webglrenderingcontext.rs b/components/script/dom/webglrenderingcontext.rs
index dbb774ad87b..a7418921e8a 100644
--- a/components/script/dom/webglrenderingcontext.rs
+++ b/components/script/dom/webglrenderingcontext.rs
@@ -987,6 +987,15 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.3
     fn DepthRange(&self, near: f32, far: f32) {
+        // From the WebGL 1.0 spec, 6.12: Viewport Depth Range:
+        //
+        //     "A call to depthRange will generate an
+        //      INVALID_OPERATION error if zNear is greater than
+        //      zFar."
+        if near > far {
+            return self.webgl_error(InvalidOperation);
+        }
+
         self.ipc_renderer
             .send(CanvasMsg::WebGL(WebGLCommand::DepthRange(near as f64, far as f64)))
             .unwrap()