From c807cab3001b1676a8f9c47811629f621027e8b2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <me@emiliocobos.me>
Date: Tue, 19 Apr 2016 13:09:06 +0200
Subject: [PATCH] webgl: Validate that the texture should be power of two if
 the level is greater than 1

---
 components/script/dom/webglrenderingcontext.rs | 18 ++++++++++++++----
 components/script/dom/webgltexture.rs          |  4 ++++
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/components/script/dom/webglrenderingcontext.rs b/components/script/dom/webglrenderingcontext.rs
index 710b61fc162..408558d3031 100644
--- a/components/script/dom/webglrenderingcontext.rs
+++ b/components/script/dom/webglrenderingcontext.rs
@@ -304,10 +304,13 @@ impl WebGLRenderingContext {
 
         //  If an attempt is made to call this function with no
         //  WebGLTexture bound, an INVALID_OPERATION error is generated.
-        if texture.is_none() {
-            self.webgl_error(InvalidOperation);
-            return false;
-        }
+        let texture = match texture {
+            Some(texture) => texture,
+            None => {
+                self.webgl_error(InvalidOperation);
+                return false;
+            }
+        };
 
         // GL_INVALID_ENUM is generated if data_type is not an accepted value.
         match data_type {
@@ -372,6 +375,13 @@ impl WebGLRenderingContext {
             return false;
         }
 
+        // GL_INVALID_VALUE is generated if level is greater than zero and the
+        // texture and the texture is not power of two.
+        if level > 0 && !texture.is_power_of_two() {
+            self.webgl_error(InvalidValue);
+            return false;
+        }
+
         // GL_INVALID_VALUE is generated if border is not 0.
         if border != 0 {
             self.webgl_error(InvalidValue);
diff --git a/components/script/dom/webgltexture.rs b/components/script/dom/webgltexture.rs
index 5bb7d5ff734..f39fa9b5789 100644
--- a/components/script/dom/webgltexture.rs
+++ b/components/script/dom/webgltexture.rs
@@ -227,6 +227,10 @@ impl WebGLTexture {
         }
     }
 
+    pub fn is_power_of_two(&self) -> bool {
+        self.image_info_at_face(0, 0).is_power_of_two()
+    }
+
     pub fn populate_mip_chain(&self, first_level: u32, last_level: u32) -> WebGLResult<()> {
         let base_image_info = self.image_info_at_face(0, first_level);
         if !base_image_info.is_initialized() {