Make some WebGL parameters non-optional (fixes #8753)

Those parameters aren't optional in the current spec.

The test element-array-buffer-delete-recreate.html now fails because we don't
actually implement gl.getParameter(gl.CURRENT_PROGRAM).

components/script/dom/webglrenderingcontext.rs

@@ -16,7 +16,7 @@ use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderi
 use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextMethods;
 use dom::bindings::codegen::UnionTypes::ImageDataOrHTMLImageElementOrHTMLCanvasElementOrHTMLVideoElement;
 use dom::bindings::conversions::{ConversionResult, FromJSValConvertible, ToJSValConvertible};
-use dom::bindings::error::{Error, Fallible};
+use dom::bindings::error::{Error, ErrorResult, Fallible};
 use dom::bindings::inheritance::Castable;
 use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
 use dom::bindings::root::{Dom, DomRoot, LayoutDom, MutNullableDom};
@@ -763,14 +763,10 @@ impl WebGLRenderingContext {
         }
     }
 
-    fn get_image_pixels(&self,
-                        source: Option<ImageDataOrHTMLImageElementOrHTMLCanvasElementOrHTMLVideoElement>)
-                        -> ImagePixelResult {
-        let source = match source {
-            Some(s) => s,
-            None => return Err(()),
-        };
-
+    fn get_image_pixels(
+        &self,
+        source: ImageDataOrHTMLImageElementOrHTMLCanvasElementOrHTMLVideoElement,
+    ) -> ImagePixelResult {
         // NOTE: Getting the pixels probably can be short-circuited if some
         // parameter is invalid.
         //
@@ -1965,10 +1961,8 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
-    fn CompileShader(&self, shader: Option<&WebGLShader>) {
-        if let Some(shader) = shader {
-            shader.compile(self.webgl_version, self.glsl_version, &self.extension_manager)
-        }
+    fn CompileShader(&self, shader: &WebGLShader) {
+        shader.compile(self.webgl_version, self.glsl_version, &self.extension_manager)
     }
 
     // TODO(emilio): Probably in the future we should keep track of the
@@ -2244,23 +2238,7 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.10
-    fn GetActiveUniform(&self, program: Option<&WebGLProgram>, index: u32) -> Option<DomRoot<WebGLActiveInfo>> {
-        let program = match program {
-            Some(program) => program,
-            None => {
-                // Reasons to generate InvalidValue error
-                // From the GLES 2.0 spec
-                //
-                //     "INVALID_VALUE is generated if index is greater than or equal
-                //      to the number of active uniform variables in program"
-                //
-                // A null program has no uniforms so any index is always greater than the active uniforms
-                // WebGl conformance expects error with null programs. Check tests in get-active-test.html
-                self.webgl_error(InvalidValue);
-                return None;
-            }
-        };
-
+    fn GetActiveUniform(&self, program: &WebGLProgram, index: u32) -> Option<DomRoot<WebGLActiveInfo>> {
         match program.get_active_uniform(index) {
             Ok(ret) => Some(ret),
             Err(e) => {
@@ -2271,23 +2249,7 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.10
-    fn GetActiveAttrib(&self, program: Option<&WebGLProgram>, index: u32) -> Option<DomRoot<WebGLActiveInfo>> {
-        let program = match program {
-            Some(program) => program,
-            None => {
-                // Reasons to generate InvalidValue error
-                // From the GLES 2.0 spec
-                //
-                //     "INVALID_VALUE is generated if index is greater than or equal
-                //      to the number of active attribute variables in program"
-                //
-                // A null program has no attributes so any index is always greater than the active uniforms
-                // WebGl conformance expects error with null programs. Check tests in get-active-test.html
-                self.webgl_error(InvalidValue);
-                return None;
-            }
-        };
-
+    fn GetActiveAttrib(&self, program: &WebGLProgram, index: u32) -> Option<DomRoot<WebGLActiveInfo>> {
         match program.get_active_attrib(index) {
             Ok(ret) => Some(ret),
             Err(e) => {
@@ -2298,12 +2260,8 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.10
-    fn GetAttribLocation(&self, program: Option<&WebGLProgram>, name: DOMString) -> i32 {
-        if let Some(program) = program {
-            handle_potential_webgl_error!(self, program.get_attrib_location(name), None).unwrap_or(-1)
-        } else {
-            -1
-        }
+    fn GetAttribLocation(&self, program: &WebGLProgram, name: DOMString) -> i32 {
+        handle_potential_webgl_error!(self, program.get_attrib_location(name), None).unwrap_or(-1)
     }
 
     #[allow(unsafe_code)]
@@ -2394,61 +2352,48 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
-    fn GetProgramInfoLog(&self, program: Option<&WebGLProgram>) -> Option<DOMString> {
-        if let Some(program) = program {
-            match program.get_info_log() {
-                Ok(value) => Some(DOMString::from(value)),
-                Err(e) => {
-                    self.webgl_error(e);
-                    None
-                }
+    fn GetProgramInfoLog(&self, program: &WebGLProgram) -> Option<DOMString> {
+        match program.get_info_log() {
+            Ok(value) => Some(DOMString::from(value)),
+            Err(e) => {
+                self.webgl_error(e);
+                None
             }
-        } else {
-            self.webgl_error(WebGLError::InvalidValue);
-            None
         }
     }
 
     #[allow(unsafe_code)]
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
-    unsafe fn GetProgramParameter(&self, _: *mut JSContext, program: Option<&WebGLProgram>, param_id: u32) -> JSVal {
-        if let Some(program) = program {
-            match handle_potential_webgl_error!(self, program.parameter(param_id), WebGLParameter::Invalid) {
-                WebGLParameter::Int(val) => Int32Value(val),
-                WebGLParameter::Bool(val) => BooleanValue(val),
-                WebGLParameter::String(_) => panic!("Program parameter should not be string"),
-                WebGLParameter::Float(_) => panic!("Program parameter should not be float"),
-                WebGLParameter::FloatArray(_) => {
-                    panic!("Program paramenter should not be float array")
-                }
-                WebGLParameter::Invalid => NullValue(),
+    unsafe fn GetProgramParameter(&self, _: *mut JSContext, program: &WebGLProgram, param_id: u32) -> JSVal {
+        match handle_potential_webgl_error!(self, program.parameter(param_id), WebGLParameter::Invalid) {
+            WebGLParameter::Int(val) => Int32Value(val),
+            WebGLParameter::Bool(val) => BooleanValue(val),
+            WebGLParameter::String(_) => panic!("Program parameter should not be string"),
+            WebGLParameter::Float(_) => panic!("Program parameter should not be float"),
+            WebGLParameter::FloatArray(_) => {
+                panic!("Program paramenter should not be float array")
             }
-        } else {
-            NullValue()
+            WebGLParameter::Invalid => NullValue(),
         }
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
-    fn GetShaderInfoLog(&self, shader: Option<&WebGLShader>) -> Option<DOMString> {
-        shader.and_then(|s| s.info_log()).map(DOMString::from)
+    fn GetShaderInfoLog(&self, shader: &WebGLShader) -> Option<DOMString> {
+        shader.info_log().map(DOMString::from)
     }
 
     #[allow(unsafe_code)]
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
-    unsafe fn GetShaderParameter(&self, _: *mut JSContext, shader: Option<&WebGLShader>, param_id: u32) -> JSVal {
-        if let Some(shader) = shader {
-            match handle_potential_webgl_error!(self, shader.parameter(param_id), WebGLParameter::Invalid) {
-                WebGLParameter::Int(val) => Int32Value(val),
-                WebGLParameter::Bool(val) => BooleanValue(val),
-                WebGLParameter::String(_) => panic!("Shader parameter should not be string"),
-                WebGLParameter::Float(_) => panic!("Shader parameter should not be float"),
-                WebGLParameter::FloatArray(_) => {
-                    panic!("Shader paramenter should not be float array")
-                }
-                WebGLParameter::Invalid => NullValue(),
+    unsafe fn GetShaderParameter(&self, _: *mut JSContext, shader: &WebGLShader, param_id: u32) -> JSVal {
+        match handle_potential_webgl_error!(self, shader.parameter(param_id), WebGLParameter::Invalid) {
+            WebGLParameter::Int(val) => Int32Value(val),
+            WebGLParameter::Bool(val) => BooleanValue(val),
+            WebGLParameter::String(_) => panic!("Shader parameter should not be string"),
+            WebGLParameter::Float(_) => panic!("Shader parameter should not be float"),
+            WebGLParameter::FloatArray(_) => {
+                panic!("Shader paramenter should not be float array")
             }
-        } else {
-            NullValue()
+            WebGLParameter::Invalid => NullValue(),
         }
     }
 
@@ -2481,12 +2426,13 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.10
-    fn GetUniformLocation(&self,
-                          program: Option<&WebGLProgram>,
-                          name: DOMString) -> Option<DomRoot<WebGLUniformLocation>> {
-        program.and_then(|p| {
-            handle_potential_webgl_error!(self, p.get_uniform_location(name), None)
-                .map(|location| WebGLUniformLocation::new(self.global().as_window(), location, p.id()))
+    fn GetUniformLocation(
+        &self,
+        program: &WebGLProgram,
+        name: DOMString,
+    ) -> Option<DomRoot<WebGLUniformLocation>> {
+        handle_potential_webgl_error!(self, program.get_uniform_location(name), None).map(|location| {
+            WebGLUniformLocation::new(self.global().as_window(), location, program.id())
         })
     }
 
@@ -2863,15 +2809,13 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
-    fn ShaderSource(&self, shader: Option<&WebGLShader>, source: DOMString) {
-        if let Some(shader) = shader {
-            shader.set_source(source)
-        }
+    fn ShaderSource(&self, shader: &WebGLShader, source: DOMString) {
+        shader.set_source(source)
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
-    fn GetShaderSource(&self, shader: Option<&WebGLShader>) -> Option<DOMString> {
-        shader.and_then(|s| s.source())
+    fn GetShaderSource(&self, shader: &WebGLShader) -> Option<DOMString> {
+        shader.source()
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.10
@@ -3162,11 +3106,9 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
-    fn ValidateProgram(&self, program: Option<&WebGLProgram>) {
-        if let Some(program) = program {
-            if let Err(e) = program.validate() {
-                self.webgl_error(e);
-            }
+    fn ValidateProgram(&self, program: &WebGLProgram) {
+        if let Err(e) = program.validate() {
+            self.webgl_error(e);
         }
     }
 
@@ -3376,13 +3318,15 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.8
-    fn TexImage2D_(&self,
-                   target: u32,
-                   level: i32,
-                   internal_format: u32,
-                   format: u32,
-                   data_type: u32,
-                   source: Option<ImageDataOrHTMLImageElementOrHTMLCanvasElementOrHTMLVideoElement>) -> Fallible<()> {
+    fn TexImage2D_(
+        &self,
+        target: u32,
+        level: i32,
+        internal_format: u32,
+        format: u32,
+        data_type: u32,
+        source: ImageDataOrHTMLImageElementOrHTMLCanvasElementOrHTMLVideoElement,
+    ) -> ErrorResult {
         if !self.extension_manager.is_tex_type_enabled(data_type) {
             return Ok(self.webgl_error(InvalidEnum));
         }
@@ -3537,15 +3481,16 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.8
-    fn TexSubImage2D_(&self,
-                      target: u32,
-                      level: i32,
-                      xoffset: i32,
-                      yoffset: i32,
-                      format: u32,
-                      data_type: u32,
-                      source: Option<ImageDataOrHTMLImageElementOrHTMLCanvasElementOrHTMLVideoElement>)
-                      -> Fallible<()> {
+    fn TexSubImage2D_(
+        &self,
+        target: u32,
+        level: i32,
+        xoffset: i32,
+        yoffset: i32,
+        format: u32,
+        data_type: u32,
+        source: ImageDataOrHTMLImageElementOrHTMLCanvasElementOrHTMLVideoElement,
+    ) -> ErrorResult {
         let (pixels, size, premultiplied) = match self.get_image_pixels(source) {
             Ok((pixels, size, premultiplied)) => (pixels, size, premultiplied),
             Err(_) => return Ok(()),