implement missing steps from "prepare a script" algorithm

Fixes #4089

3 files changed, 39 insertions, 9 deletions

diff --git a/components/script/dom/bindings/trace.rs b/components/script/dom/bindings/trace.rs
index b7d677a5878..190f8d5166b 100644
--- a/components/script/dom/bindings/trace.rs
+++ b/components/script/dom/bindings/trace.rs
@@ -35,6 +35,7 @@ use dom::bindings::utils::{Reflectable, Reflector, WindowProxyHandler};
 use script_task::ScriptChan;
 
 use cssparser::RGBA;
+use encoding::types::EncodingRef;
 use geom::matrix2d::Matrix2D;
 use geom::rect::Rect;
 use html5ever::tree_builder::QuirksMode;
@@ -78,6 +79,8 @@ impl<T: Reflectable> JSTraceable for JS<T> {
     }
 }
 
+no_jsmanaged_fields!(EncodingRef);
+
 no_jsmanaged_fields!(Reflector);
 
 /// Trace a `JSVal`.
diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 6e5413ebdc8..9abb356345e 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -120,6 +120,9 @@ pub struct Document {
     focused: MutNullableJS<Element>,
     /// The script element that is currently executing.
     current_script: MutNullableJS<HTMLScriptElement>,
+    /// https://html.spec.whatwg.org/multipage/webappapis.html#concept-n-noscript
+    /// True if scripting is enabled for all scripts in this document
+    scripting_enabled: Cell<bool>,
 }
 
 impl DocumentDerived for EventTarget {
@@ -203,6 +206,7 @@ pub trait DocumentHelpers<'a> {
     fn find_fragment_node(self, fragid: DOMString) -> Option<Temporary<Element>>;
     fn set_ready_state(self, state: DocumentReadyState);
     fn get_focused_element(self) -> Option<Temporary<Element>>;
+    fn is_scripting_enabled(self) -> bool;
     fn begin_focus_transaction(self);
     fn request_focus(self, elem: JSRef<Element>);
     fn commit_focus_transaction(self);
@@ -389,6 +393,11 @@ impl<'a> DocumentHelpers<'a> for JSRef<'a, Document> {
         let _ = event.r().fire(target);
     }
 
+    /// Return whether scripting is enabled or not
+    fn is_scripting_enabled(self) -> bool {
+        self.scripting_enabled.get()
+    }
+
     /// Return the element that currently has focus.
     // https://dvcs.w3.org/hg/dom3events/raw-file/tip/html/DOM3-Events.html#events-focusevent-doc-focus
     fn get_focused_element(self) -> Option<Temporary<Element>> {
@@ -710,6 +719,7 @@ impl Document {
             possibly_focused: Default::default(),
             focused: Default::default(),
             current_script: Default::default(),
+            scripting_enabled: Cell::new(true),
         }
     }
 
diff --git a/components/script/dom/htmlscriptelement.rs b/components/script/dom/htmlscriptelement.rs
index 853d6709fcb..3371d144a1e 100644
--- a/components/script/dom/htmlscriptelement.rs
+++ b/components/script/dom/htmlscriptelement.rs
@@ -6,6 +6,7 @@ use std::ascii::AsciiExt;
 
 use dom::attr::Attr;
 use dom::attr::AttrHelpers;
+use dom::bindings::cell::DOMRefCell;
 use dom::bindings::codegen::Bindings::AttrBinding::AttrMethods;
 use dom::bindings::codegen::Bindings::DocumentBinding::DocumentMethods;
 use dom::bindings::codegen::Bindings::HTMLScriptElementBinding;
@@ -15,8 +16,9 @@ use dom::bindings::codegen::InheritTypes::{HTMLScriptElementDerived, HTMLScriptE
 use dom::bindings::codegen::InheritTypes::{ElementCast, HTMLElementCast, NodeCast};
 use dom::bindings::codegen::InheritTypes::EventTargetCast;
 use dom::bindings::global::GlobalRef;
-use dom::bindings::js::{JSRef, Temporary, OptionalRootable, RootedReference};
+use dom::bindings::js::{JS, JSRef, Temporary, OptionalRootable, RootedReference};
 use dom::bindings::refcounted::Trusted;
+use dom::bindings::trace::JSTraceable;
 use dom::document::{Document, DocumentHelpers};
 use dom::element::{Element, AttributeHandlers, ElementCreator};
 use dom::eventtarget::{EventTarget, EventTargetTypeId};
@@ -29,7 +31,8 @@ use dom::window::ScriptHelpers;
 use script_task::{ScriptMsg, Runnable};
 
 use encoding::all::UTF_8;
-use encoding::types::{Encoding, DecoderTrap};
+use encoding::label::encoding_from_whatwg_label;
+use encoding::types::{Encoding, EncodingRef, DecoderTrap};
 use net::resource_task::{load_whole_resource, Metadata};
 use util::str::{DOMString, HTML_SPACE_CHARACTERS, StaticStringVec};
 use std::borrow::ToOwned;
@@ -56,6 +59,12 @@ pub struct HTMLScriptElement {
     ///
     /// (currently unused)
     ready_to_be_parser_executed: Cell<bool>,
+
+    /// Document of the parser that created this element
+    parser_document: JS<Document>,
+
+    /// https://html.spec.whatwg.org/multipage/scripting.html#concept-script-encoding
+    block_character_encoding: DOMRefCell<EncodingRef>,
 }
 
 impl HTMLScriptElementDerived for EventTarget {
@@ -73,6 +82,8 @@ impl HTMLScriptElement {
             parser_inserted: Cell::new(creator == ElementCreator::ParserCreated),
             non_blocking: Cell::new(creator != ElementCreator::ParserCreated),
             ready_to_be_parser_executed: Cell::new(false),
+            parser_document: JS::from_rooted(document),
+            block_character_encoding: DOMRefCell::new(UTF_8 as EncodingRef),
         }
     }
 
@@ -179,12 +190,16 @@ impl<'a> HTMLScriptElementHelpers for JSRef<'a, HTMLScriptElement> {
         self.already_started.set(true);
 
         // Step 10.
-        // TODO: If the element is flagged as "parser-inserted", but the element's node document is
-        // not the Document of the parser that created the element, then abort these steps.
+        let document_from_node_ref = document_from_node(self).root();
+        let document_from_node_ref = document_from_node_ref.r();
+        if self.parser_inserted.get() && self.parser_document.root().r() != document_from_node_ref {
+            return;
+        }
 
         // Step 11.
-        // TODO: If scripting is disabled for the script element, then the user agent must abort
-        // these steps at this point. The script is not executed.
+        if !document_from_node_ref.is_scripting_enabled() {
+            return;
+        }
 
         // Step 12.
         match element.get_attribute(ns!(""), &atom!("for")).root() {
@@ -207,9 +222,11 @@ impl<'a> HTMLScriptElementHelpers for JSRef<'a, HTMLScriptElement> {
             _ => { }
         }
         // Step 13.
-        // TODO: If the script element has a `charset` attribute, then let the script block's
-        // character encoding for this script element be the result of getting an encoding from the
-        // value of the `charset` attribute.
+        if let Some(charset) = element.get_attribute(ns!(""), &Atom::from_slice("charset")).root() {
+            if let Some(encodingRef) = encoding_from_whatwg_label(&charset.r().Value()) {
+                *self.block_character_encoding.borrow_mut() = encodingRef;
+            }
+        }
 
         // Step 14.
         let window = window_from_node(self).root();