Auto merge of #21207 - servo:webgl, r=emilio

Some WebGL drive-by fixes

<!-- Reviewable:start -->
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/21207)
<!-- Reviewable:end -->

components/script/dom/webglprogram.rs

@@ -28,6 +28,7 @@ pub struct WebGLProgram {
     is_deleted: Cell<bool>,
     link_called: Cell<bool>,
     linked: Cell<bool>,
+    link_generation: Cell<u64>,
     fragment_shader: MutNullableDom<WebGLShader>,
     vertex_shader: MutNullableDom<WebGLShader>,
     #[ignore_malloc_size_of = "Defined in ipc-channel"]
@@ -37,15 +38,14 @@ pub struct WebGLProgram {
 }
 
 impl WebGLProgram {
-    fn new_inherited(renderer: WebGLMsgSender,
+    fn new_inherited(renderer: WebGLMsgSender, id: WebGLProgramId) -> Self {
-                     id: WebGLProgramId)
+        Self {
-                     -> WebGLProgram {
-        WebGLProgram {
             webgl_object: WebGLObject::new_inherited(),
             id: id,
             is_deleted: Cell::new(false),
             link_called: Cell::new(false),
             linked: Cell::new(false),
+            link_generation: Default::default(),
             fragment_shader: Default::default(),
             vertex_shader: Default::default(),
             renderer: renderer,
@@ -109,7 +109,9 @@ impl WebGLProgram {
             return Err(WebGLError::InvalidOperation);
         }
         self.linked.set(false);
-        *self.active_attribs.borrow_mut() = vec![].into();
+        self.link_generation.set(self.link_generation.get().checked_add(1).unwrap());
+        *self.active_attribs.borrow_mut() = Box::new([]);
+        *self.active_uniforms.borrow_mut() = Box::new([]);
 
         match self.fragment_shader.get() {
             Some(ref shader) if shader.successfully_compiled() => {},
@@ -354,7 +356,14 @@ impl WebGLProgram {
             .unwrap();
         let location = receiver.recv().unwrap();
 
-        Ok(Some(WebGLUniformLocation::new(self.global().as_window(), location, self.id, size, type_)))
+        Ok(Some(WebGLUniformLocation::new(
+            self.global().as_window(),
+            location,
+            self.id,
+            self.link_generation.get(),
+            size,
+            type_,
+        )))
     }
 
     /// glGetProgramInfoLog
@@ -388,6 +397,10 @@ impl WebGLProgram {
             (None, None) => vec![]
         })
     }
+
+    pub fn link_generation(&self) -> u64 {
+        self.link_generation.get()
+    }
 }
 
 impl Drop for WebGLProgram {

components/script/dom/webglrenderingcontext.rs

@@ -436,7 +436,10 @@ impl WebGLRenderingContext {
             None => return,
         };
         match self.current_program.get() {
-            Some(ref program) if program.id() == location.program_id() => {}
+            Some(ref program) if
+                program.id() == location.program_id() &&
+                program.link_generation() == location.link_generation()
+            => {}
             _ => return self.webgl_error(InvalidOperation),
         }
         handle_potential_webgl_error!(self, f(location));
@@ -3612,7 +3615,12 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     ) -> JSVal {
         // FIXME(nox): https://github.com/servo/servo/issues/21133
 
-        if program.is_deleted() || !program.is_linked() || program.id() != location.program_id() {
+        if
+            program.is_deleted() ||
+            !program.is_linked() ||
+            program.id() != location.program_id() ||
+            program.link_generation() != location.link_generation()
+        {
             self.webgl_error(InvalidOperation);
             return NullValue();
         }

components/script/dom/webgluniformlocation.rs

@@ -15,6 +15,7 @@ pub struct WebGLUniformLocation {
     reflector_: Reflector,
     id: i32,
     program_id: WebGLProgramId,
+    link_generation: u64,
     size: Option<i32>,
     type_: u32,
 }
@@ -23,6 +24,7 @@ impl WebGLUniformLocation {
     fn new_inherited(
         id: i32,
         program_id: WebGLProgramId,
+        link_generation: u64,
         size: Option<i32>,
         type_: u32,
     ) -> Self {
@@ -30,6 +32,7 @@ impl WebGLUniformLocation {
             reflector_: Reflector::new(),
             id,
             program_id,
+            link_generation,
             size,
             type_,
         }
@@ -39,11 +42,12 @@ impl WebGLUniformLocation {
         window: &Window,
         id: i32,
         program_id: WebGLProgramId,
+        link_generation: u64,
         size: Option<i32>,
         type_: u32,
     ) -> DomRoot<Self> {
         reflect_dom_object(
-            Box::new(Self::new_inherited(id, program_id, size, type_)),
+            Box::new(Self::new_inherited(id, program_id, link_generation, size, type_)),
             window,
             WebGLUniformLocationBinding::Wrap,
         )
@@ -57,6 +61,10 @@ impl WebGLUniformLocation {
         self.program_id
     }
 
+    pub fn link_generation(&self) -> u64 {
+        self.link_generation
+    }
+
     pub fn size(&self) -> Option<i32> {
         self.size
     }

tests/wpt/mozilla/meta/webgl/conformance-1.0.3/conformance/uniforms/uniform-location.html.ini

@@ -1,7 +0,0 @@
-[uniform-location.html]
-  [WebGL test #20: getError expected: INVALID_OPERATION. Was NO_ERROR : after evaluating: contextA.uniform1i(locationSx, 3)]
-    expected: FAIL
-
-  [WebGL test #21: getError expected: INVALID_OPERATION. Was NO_ERROR : after evaluating: contextA.getUniform(programS, locationSx)]
-    expected: FAIL
-