Auto merge of #5916 - servo:prepare-rustup, r=jdm

<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/5916)
<!-- Reviewable:end -->

9 files changed, 59 insertions, 50 deletions

diff --git a/components/script/dom/bindings/conversions.rs b/components/script/dom/bindings/conversions.rs
index aa509ad5927..5055921bb3a 100644
--- a/components/script/dom/bindings/conversions.rs
+++ b/components/script/dom/bindings/conversions.rs
@@ -400,9 +400,8 @@ impl FromJSValConvertible for USVString {
 impl ToJSValConvertible for ByteString {
     fn to_jsval(&self, cx: *mut JSContext) -> JSVal {
         unsafe {
-            let slice = self.as_slice();
-            let jsstr = JS_NewStringCopyN(cx, slice.as_ptr() as *const libc::c_char,
-                                          slice.len() as libc::size_t);
+            let jsstr = JS_NewStringCopyN(cx, self.as_ptr() as *const libc::c_char,
+                                          self.len() as libc::size_t);
             if jsstr.is_null() {
                 panic!("JS_NewStringCopyN failed");
             }
diff --git a/components/script/dom/bindings/js.rs b/components/script/dom/bindings/js.rs
index c80aa48b4ac..70dd88c1842 100644
--- a/components/script/dom/bindings/js.rs
+++ b/components/script/dom/bindings/js.rs
@@ -593,7 +593,7 @@ impl RootCollection {
 /// `RootCollection` object. Attempts to transfer ownership of a `Root` via
 /// moving will trigger dynamic unrooting failures due to incorrect ordering.
 #[no_move]
-pub struct Root<T> {
+pub struct Root<T: Reflectable> {
     /// List that ensures correct dynamic root ordering
     root_list: &'static RootCollection,
     /// Reference to rooted value that must not outlive this container
diff --git a/components/script/dom/bindings/refcounted.rs b/components/script/dom/bindings/refcounted.rs
index 8a626ac6b67..204ef93e023 100644
--- a/components/script/dom/bindings/refcounted.rs
+++ b/components/script/dom/bindings/refcounted.rs
@@ -47,7 +47,7 @@ unsafe impl Send for TrustedReference {}
 /// shared among tasks for use in asynchronous operations. The underlying
 /// DOM object is guaranteed to live at least as long as the last outstanding
 /// `Trusted<T>` instance.
-pub struct Trusted<T> {
+pub struct Trusted<T: Reflectable> {
     /// A pointer to the Rust DOM object of type T, but void to allow
     /// sending `Trusted<T>` between tasks, regardless of T's sendability.
     ptr: *const libc::c_void,
diff --git a/components/script/dom/bindings/str.rs b/components/script/dom/bindings/str.rs
index fff381e98f8..b8c0af0caa6 100644
--- a/components/script/dom/bindings/str.rs
+++ b/components/script/dom/bindings/str.rs
@@ -4,8 +4,10 @@
 
 //! The `ByteString` struct.
 
+use std::ascii::AsciiExt;
 use std::borrow::ToOwned;
 use std::hash::{Hash, Hasher};
+use std::ops;
 use std::str;
 use std::str::FromStr;
 
@@ -27,12 +29,6 @@ impl ByteString {
         str::from_utf8(&vec).ok()
     }
 
-    /// Returns the underlying vector as a slice.
-    pub fn as_slice<'a>(&'a self) -> &'a [u8] {
-        let ByteString(ref vector) = *self;
-        vector
-    }
-
     /// Returns the length.
     pub fn len(&self) -> usize {
         let ByteString(ref vector) = *self;
@@ -41,20 +37,12 @@ impl ByteString {
 
     /// Compare `self` to `other`, matching A–Z and a–z as equal.
     pub fn eq_ignore_case(&self, other: &ByteString) -> bool {
-        // XXXManishearth make this more efficient
-        self.to_lower() == other.to_lower()
+        self.0.eq_ignore_ascii_case(&other.0)
     }
 
     /// Returns `self` with A–Z replaced by a–z.
     pub fn to_lower(&self) -> ByteString {
-        let ByteString(ref vec) = *self;
-        ByteString::new(vec.iter().map(|&x| {
-            if x > 'A' as u8 && x < 'Z' as u8 {
-                x + ('a' as u8) - ('A' as u8)
-            } else {
-                x
-            }
-        }).collect())
+        ByteString::new(self.0.to_ascii_lowercase())
     }
 
     /// Returns whether `self` is a `token`, as defined by
@@ -158,6 +146,13 @@ impl FromStr for ByteString {
     }
 }
 
+impl ops::Deref for ByteString {
+    type Target = [u8];
+    fn deref(&self) -> &[u8] {
+        &self.0
+    }
+}
+
 /// A string that is constructed from a UCS-2 buffer by replacing invalid code
 /// points with the replacement character.
 pub struct USVString(pub String);
diff --git a/components/script/dom/bindings/trace.rs b/components/script/dom/bindings/trace.rs
index c25b0addc47..14d23920ab9 100644
--- a/components/script/dom/bindings/trace.rs
+++ b/components/script/dom/bindings/trace.rs
@@ -99,7 +99,7 @@ pub fn trace_jsval(tracer: *mut JSTracer, description: &str, val: JSVal) {
     unsafe {
         let name = CString::new(description).unwrap();
         (*tracer).debugPrinter = None;
-        (*tracer).debugPrintIndex = -1;
+        (*tracer).debugPrintIndex = !0;
         (*tracer).debugPrintArg = name.as_ptr() as *const libc::c_void;
         debug!("tracing value {}", description);
         JS_CallTracer(tracer, val.to_gcthing(), val.trace_kind());
@@ -117,7 +117,7 @@ pub fn trace_object(tracer: *mut JSTracer, description: &str, obj: *mut JSObject
     unsafe {
         let name = CString::new(description).unwrap();
         (*tracer).debugPrinter = None;
-        (*tracer).debugPrintIndex = -1;
+        (*tracer).debugPrintIndex = !0;
         (*tracer).debugPrintArg = name.as_ptr() as *const libc::c_void;
         debug!("tracing {}", description);
         JS_CallTracer(tracer, obj as *mut libc::c_void, JSGCTraceKind::JSTRACE_OBJECT);
@@ -318,16 +318,20 @@ impl JSTraceable for () {
 
 /// Holds a set of vectors that need to be rooted
 pub struct RootedCollectionSet {
-    set: Vec<HashSet<*const RootedVec<()>>>
+    set: Vec<HashSet<*const RootedVec<Void>>>
 }
 
 /// TLV Holds a set of vectors that need to be rooted
 thread_local!(pub static ROOTED_COLLECTIONS: Rc<RefCell<RootedCollectionSet>> =
               Rc::new(RefCell::new(RootedCollectionSet::new())));
 
-enum CollectionType {
+/// Type of `RootedVec`
+pub enum CollectionType {
+    /// DOM objects
     DOMObjects,
+    /// `JSVal`s
     JSVals,
+    /// `*mut JSObject`s
     JSObjects,
 }
 
@@ -356,10 +360,12 @@ impl RootedCollectionSet {
     }
 
     unsafe fn trace(&self, tracer: *mut JSTracer) {
-        fn trace_collection_type<T: JSTraceable>(tracer: *mut JSTracer,
-                                                 collections: &HashSet<*const RootedVec<()>>) {
+        fn trace_collection_type<T>(tracer: *mut JSTracer,
+                                    collections: &HashSet<*const RootedVec<Void>>)
+            where T: JSTraceable + VecRootableType
+        {
             for collection in collections {
-                let collection: *const RootedVec<()> = *collection;
+                let collection: *const RootedVec<Void> = *collection;
                 let collection = collection as *const RootedVec<T>;
                 unsafe {
                     let _ = (*collection).trace(tracer);
@@ -367,10 +373,10 @@ impl RootedCollectionSet {
             }
         }
 
-        let dom_collections = &self.set[CollectionType::DOMObjects as usize] as *const _ as *const HashSet<*const RootedVec<*const Reflector>>;
+        let dom_collections = &self.set[CollectionType::DOMObjects as usize] as *const _ as *const HashSet<*const RootedVec<JS<Void>>>;
         for dom_collection in (*dom_collections).iter() {
             for reflector in (**dom_collection).iter() {
-                trace_reflector(tracer, "", &**reflector);
+                trace_reflector(tracer, "", reflector.reflector());
             }
         }
 
@@ -381,7 +387,7 @@ impl RootedCollectionSet {
 
 
 /// Trait implemented by all types that can be used with RootedVec
-trait VecRootableType {
+pub trait VecRootableType {
     /// Return the type tag used to determine how to trace RootedVec
     fn tag(_a: Option<Self>) -> CollectionType;
 }
@@ -398,11 +404,21 @@ impl VecRootableType for *mut JSObject {
     fn tag(_a: Option<*mut JSObject>) -> CollectionType { CollectionType::JSObjects }
 }
 
+enum Void {}
+
+impl VecRootableType for Void {
+    fn tag(_a: Option<Void>) -> CollectionType { unreachable!() }
+}
+
+impl Reflectable for Void {
+    fn reflector<'a>(&'a self) -> &'a Reflector { unreachable!() }
+}
+
 /// A vector of items that are rooted for the lifetime
 /// of this struct
 #[allow(unrooted_must_root)]
 #[no_move]
-pub struct RootedVec<T> {
+pub struct RootedVec<T: VecRootableType> {
     v: Vec<T>
 }
 
@@ -435,14 +451,14 @@ impl<T: VecRootableType> Drop for RootedVec<T> {
     }
 }
 
-impl<T> Deref for RootedVec<T> {
+impl<T: VecRootableType> Deref for RootedVec<T> {
     type Target = Vec<T>;
     fn deref(&self) -> &Vec<T> {
         &self.v
     }
 }
 
-impl<T> DerefMut for RootedVec<T> {
+impl<T: VecRootableType> DerefMut for RootedVec<T> {
     fn deref_mut(&mut self) -> &mut Vec<T> {
         &mut self.v
     }
diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index a936e783ad4..deb2df56b84 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -83,7 +83,7 @@ use std::borrow::{IntoCow, ToOwned};
 use std::cell::{Ref, RefMut};
 use std::default::Default;
 use std::mem;
-use std::old_io::{MemWriter, Writer};
+use std::old_io::Writer;
 use std::sync::Arc;
 
 #[dom_struct]
@@ -571,13 +571,13 @@ impl<'a> ElementHelpers<'a> for JSRef<'a, Element> {
 
     fn serialize(self, traversal_scope: TraversalScope) -> Fallible<DOMString> {
         let node: JSRef<Node> = NodeCast::from_ref(self);
-        let mut writer = MemWriter::new();
+        let mut writer = vec![];
         match serialize(&mut writer, &node,
                         SerializeOpts {
                             traversal_scope: traversal_scope,
                             .. Default::default()
                         }) {
-            Ok(()) => Ok(String::from_utf8(writer.into_inner()).unwrap()),
+            Ok(()) => Ok(String::from_utf8(writer).unwrap()),
             Err(_) => panic!("Cannot serialize element"),
         }
     }
diff --git a/components/script/dom/macros.rs b/components/script/dom/macros.rs
index 76157789e71..b3dda8730e0 100644
--- a/components/script/dom/macros.rs
+++ b/components/script/dom/macros.rs
@@ -85,12 +85,11 @@ macro_rules! make_url_or_base_getter(
             use std::ascii::AsciiExt;
             let element: JSRef<Element> = ElementCast::from_ref(self);
             let url = element.get_url_attribute(&Atom::from_slice($htmlname));
-            match &*url {
-                "" => {
-                    let window = window_from_node(self).root();
-                    window.r().get_url().serialize()
-                },
-                _ => url
+            if url.is_empty() {
+                let window = window_from_node(self).root();
+                window.r().get_url().serialize()
+            } else {
+                url
             }
         }
     );
diff --git a/components/script/dom/textencoder.rs b/components/script/dom/textencoder.rs
index 91a02257d71..75d2badd9e6 100644
--- a/components/script/dom/textencoder.rs
+++ b/components/script/dom/textencoder.rs
@@ -80,12 +80,12 @@ impl<'a> TextEncoderMethods for JSRef<'a, TextEncoder> {
     #[allow(unsafe_code)]
     fn Encode(self, cx: *mut JSContext, input: USVString) -> *mut JSObject {
         unsafe {
-            let output = self.encoder.encode(&input.0, EncoderTrap::Strict).unwrap();
-            let length = output.len() as u32;
+            let encoded = self.encoder.encode(&input.0, EncoderTrap::Strict).unwrap();
+            let length = encoded.len() as u32;
             let js_object: *mut JSObject = JS_NewUint8Array(cx, length);
 
             let js_object_data: *mut uint8_t = JS_GetUint8ArrayData(js_object, cx);
-            ptr::copy_nonoverlapping(js_object_data, output.as_ptr(), length as usize);
+            ptr::copy_nonoverlapping(js_object_data, encoded.as_ptr(), length as usize);
             return js_object;
         }
     }
diff --git a/components/script/dom/xmlhttprequest.rs b/components/script/dom/xmlhttprequest.rs
index 73748b27f14..d9e0f57ad8d 100644
--- a/components/script/dom/xmlhttprequest.rs
+++ b/components/script/dom/xmlhttprequest.rs
@@ -399,14 +399,14 @@ impl<'a> XMLHttpRequestMethods for JSRef<'a, XMLHttpRequest> {
                 debug!("SetRequestHeader: old value = {:?}", raw[0]);
                 let mut buf = raw[0].clone();
                 buf.push_all(b", ");
-                buf.push_all(value.as_slice());
+                buf.push_all(&value);
                 debug!("SetRequestHeader: new value = {:?}", buf);
                 value = ByteString::new(buf);
             },
             None => {}
         }
 
-        headers.set_raw(name_str.to_owned(), vec![value.as_slice().to_vec()]);
+        headers.set_raw(name_str.to_owned(), vec![value.to_vec()]);
         Ok(())
     }
 
@@ -678,7 +678,7 @@ impl<'a> XMLHttpRequestMethods for JSRef<'a, XMLHttpRequest> {
             },
             _ if self.ready_state.get() != XMLHttpRequestState::Done => NullValue(),
             Json => {
-                let decoded = UTF_8.decode(self.response.borrow().as_slice(), DecoderTrap::Replace).unwrap().to_owned();
+                let decoded = UTF_8.decode(&self.response.borrow(), DecoderTrap::Replace).unwrap().to_owned();
                 let decoded: Vec<u16> = decoded.utf16_units().collect();
                 let mut vp = UndefinedValue();
                 unsafe {
@@ -1028,7 +1028,7 @@ impl<'a> PrivateXMLHttpRequestHelpers for JSRef<'a, XMLHttpRequest> {
         let response = self.response.borrow();
         // According to Simon, decode() should never return an error, so unwrap()ing
         // the result should be fine. XXXManishearth have a closer look at this later
-        encoding.decode(response.as_slice(), DecoderTrap::Replace).unwrap().to_owned()
+        encoding.decode(&response, DecoderTrap::Replace).unwrap().to_owned()
     }
     fn filter_response_headers(self) -> Headers {
         // https://fetch.spec.whatwg.org/#concept-response-header-list