Make some attr values case-insensitive in selectors

https://bugzilla.mozilla.org/show_bug.cgi?id=1363531

10 files changed, 167 insertions, 30 deletions

diff --git a/Cargo.lock b/Cargo.lock
index b21ff19f356..f9acb8824b6 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2457,6 +2457,8 @@ dependencies = [
  "cssparser 0.13.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "fnv 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "matches 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_codegen 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "precomputed-hash 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "size_of_test 0.0.1",
  "smallvec 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/components/selectors/Cargo.toml b/components/selectors/Cargo.toml
index ceef176eae1..4ca9a240c67 100644
--- a/components/selectors/Cargo.toml
+++ b/components/selectors/Cargo.toml
@@ -10,6 +10,7 @@ repository = "https://github.com/servo/servo"
 readme = "README.md"
 keywords = ["css", "selectors"]
 license = "MPL-2.0"
+build = "build.rs"
 
 [lib]
 name = "selectors"
@@ -25,8 +26,12 @@ bitflags = "0.7"
 matches = "0.1"
 cssparser = "0.13.3"
 fnv = "1.0"
+phf = "0.7.18"
 precomputed-hash = "0.1"
 smallvec = "0.3"
 
 [dev-dependencies]
 size_of_test = {path = "../size_of_test"}
+
+[build-dependencies]
+phf_codegen = "0.7.18"
diff --git a/components/selectors/attr.rs b/components/selectors/attr.rs
index f18219b2204..e8ab10ce02f 100644
--- a/components/selectors/attr.rs
+++ b/components/selectors/attr.rs
@@ -119,13 +119,29 @@ pub static SELECTOR_WHITESPACE: &'static [char] = &[' ', '\t', '\n', '\r', '\x0C
 pub enum CaseSensitivity {
     CaseSensitive,  // Selectors spec says language-defined, but HTML says sensitive.
     AsciiCaseInsensitive,
+    AsciiCaseInsensitiveIfInHtmlElementInHtmlDocument,
 }
 
 impl CaseSensitivity {
+    pub fn to_definite(self, is_html_element_in_html_document: bool) -> Self {
+        if let CaseSensitivity::AsciiCaseInsensitiveIfInHtmlElementInHtmlDocument = self {
+            if is_html_element_in_html_document {
+                CaseSensitivity::AsciiCaseInsensitive
+            } else {
+                CaseSensitivity::CaseSensitive
+            }
+        } else {
+            self
+        }
+    }
+
     pub fn eq(self, a: &[u8], b: &[u8]) -> bool {
         match self {
             CaseSensitivity::CaseSensitive => a == b,
-            CaseSensitivity::AsciiCaseInsensitive => a.eq_ignore_ascii_case(b)
+            CaseSensitivity::AsciiCaseInsensitive => a.eq_ignore_ascii_case(b),
+            CaseSensitivity::AsciiCaseInsensitiveIfInHtmlElementInHtmlDocument => {
+                unreachable!("matching.rs should have called case_sensitivity.to_definite()");
+            }
         }
     }
 
@@ -152,6 +168,9 @@ impl CaseSensitivity {
                     true
                 }
             }
+            CaseSensitivity::AsciiCaseInsensitiveIfInHtmlElementInHtmlDocument => {
+                unreachable!("matching.rs should have called case_sensitivity.to_definite()");
+            }
         }
     }
 }
diff --git a/components/selectors/build.rs b/components/selectors/build.rs
new file mode 100644
index 00000000000..0d0a40256f3
--- /dev/null
+++ b/components/selectors/build.rs
@@ -0,0 +1,75 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+extern crate phf_codegen;
+
+use std::env;
+use std::fs::File;
+use std::io::{BufWriter, Write};
+use std::path::Path;
+
+fn main() {
+    let path = Path::new(&env::var("OUT_DIR").unwrap())
+        .join("ascii_case_insensitive_html_attributes.rs");
+    let mut file = BufWriter::new(File::create(&path).unwrap());
+
+    write!(&mut file, "{{ static SET: ::phf::Set<&'static str> = ",
+    ).unwrap();
+    let mut set = phf_codegen::Set::new();
+    for name in ASCII_CASE_INSENSITIVE_HTML_ATTRIBUTES.split_whitespace() {
+        set.entry(name);
+    }
+    set.build(&mut file).unwrap();
+    write!(&mut file, "; &SET }}").unwrap();
+}
+
+/// https://html.spec.whatwg.org/multipage/#selectors
+static ASCII_CASE_INSENSITIVE_HTML_ATTRIBUTES: &'static str = r#"
+    accept
+    accept-charset
+    align
+    alink
+    axis
+    bgcolor
+    charset
+    checked
+    clear
+    codetype
+    color
+    compact
+    declare
+    defer
+    dir
+    direction
+    disabled
+    enctype
+    face
+    frame
+    hreflang
+    http-equiv
+    lang
+    language
+    link
+    media
+    method
+    multiple
+    nohref
+    noresize
+    noshade
+    nowrap
+    readonly
+    rel
+    rev
+    rules
+    scope
+    scrolling
+    selected
+    shape
+    target
+    text
+    type
+    valign
+    valuetype
+    vlink
+"#;
diff --git a/components/selectors/lib.rs b/components/selectors/lib.rs
index 5e7b4c99ce8..3e413c0c08b 100644
--- a/components/selectors/lib.rs
+++ b/components/selectors/lib.rs
@@ -6,6 +6,7 @@
 #[macro_use] extern crate cssparser;
 #[macro_use] extern crate matches;
 extern crate fnv;
+extern crate phf;
 extern crate precomputed_hash;
 #[cfg(test)] #[macro_use] extern crate size_of_test;
 extern crate smallvec;
diff --git a/components/selectors/matching.rs b/components/selectors/matching.rs
index a11708818b3..2ed6a436687 100644
--- a/components/selectors/matching.rs
+++ b/components/selectors/matching.rs
@@ -5,7 +5,7 @@
 use attr::{AttrSelectorOperation, NamespaceConstraint};
 use bloom::BloomFilter;
 use parser::{Combinator, ComplexSelector, Component, LocalName};
-use parser::{Selector, SelectorInner, SelectorIter, SelectorImpl};
+use parser::{Selector, SelectorInner, SelectorIter};
 use std::borrow::Borrow;
 use tree::Element;
 
@@ -387,7 +387,8 @@ fn matches_simple_selector<E, F>(
             element.match_pseudo_element(pseudo, context)
         }
         Component::LocalName(LocalName { ref name, ref lower_name }) => {
-            element.get_local_name() == select_name(element, name, lower_name).borrow()
+            let is_html = element.is_html_element_in_html_document();
+            element.get_local_name() == select_name(is_html, name, lower_name).borrow()
         }
         Component::ExplicitUniversalType |
         Component::ExplicitAnyNamespace => {
@@ -410,9 +411,10 @@ fn matches_simple_selector<E, F>(
             element.has_class(class)
         }
         Component::AttributeInNoNamespaceExists { ref local_name, ref local_name_lower } => {
+            let is_html = element.is_html_element_in_html_document();
             element.attr_matches(
                 &NamespaceConstraint::Specific(&::parser::namespace_empty_string::<E::Impl>()),
-                select_name(element, local_name, local_name_lower),
+                select_name(is_html, local_name, local_name_lower),
                 &AttrSelectorOperation::Exists
             )
         }
@@ -427,12 +429,13 @@ fn matches_simple_selector<E, F>(
             if never_matches {
                 false
             } else {
+                let is_html = element.is_html_element_in_html_document();
                 element.attr_matches(
                     &NamespaceConstraint::Specific(&::parser::namespace_empty_string::<E::Impl>()),
-                    select_name(element, local_name, local_name_lower),
+                    select_name(is_html, local_name, local_name_lower),
                     &AttrSelectorOperation::WithValue {
                         operator: operator,
-                        case_sensitivity: case_sensitivity,
+                        case_sensitivity: case_sensitivity.to_definite(is_html),
                         expected_value: value,
                     }
                 )
@@ -442,9 +445,10 @@ fn matches_simple_selector<E, F>(
             if attr_sel.never_matches {
                 return false
             } else {
+                let is_html = element.is_html_element_in_html_document();
                 element.attr_matches(
                     &attr_sel.namespace(),
-                    select_name(element, &attr_sel.local_name, &attr_sel.local_name_lower),
+                    select_name(is_html, &attr_sel.local_name, &attr_sel.local_name_lower),
                     &match attr_sel.operation {
                         AttrSelectorOperation::Exists => AttrSelectorOperation::Exists,
                         AttrSelectorOperation::WithValue {
@@ -454,7 +458,7 @@ fn matches_simple_selector<E, F>(
                         } => {
                             AttrSelectorOperation::WithValue {
                                 operator: operator,
-                                case_sensitivity: case_sensitivity,
+                                case_sensitivity: case_sensitivity.to_definite(is_html),
                                 expected_value: expected_value,
                             }
                         }
@@ -512,11 +516,8 @@ fn matches_simple_selector<E, F>(
     }
 }
 
-fn select_name<'a, E>(element: &E, local_name: &'a <E::Impl as SelectorImpl>::LocalName,
-                      local_name_lower: &'a <E::Impl as SelectorImpl>::LocalName)
-                      -> &'a <E::Impl as SelectorImpl>::LocalName
-where E: Element {
-    if element.is_html_element_in_html_document() {
+fn select_name<'a, T>(is_html: bool, local_name: &'a T, local_name_lower: &'a T) -> &'a T {
+    if is_html {
         local_name_lower
     } else {
         local_name
diff --git a/components/selectors/parser.rs b/components/selectors/parser.rs
index befbfd084cc..915357887fb 100644
--- a/components/selectors/parser.rs
+++ b/components/selectors/parser.rs
@@ -33,6 +33,16 @@ pub trait PseudoElement : Sized + ToCss {
     }
 }
 
+fn to_ascii_lowercase(s: &str) -> Cow<str> {
+    if let Some(first_uppercase) = s.bytes().position(|byte| byte >= b'A' && byte <= b'Z') {
+        let mut string = s.to_owned();
+        string[first_uppercase..].make_ascii_lowercase();
+        string.into()
+    } else {
+        s.into()
+    }
+}
+
 macro_rules! with_all_bounds {
     (
         [ $( $InSelector: tt )* ]
@@ -46,16 +56,6 @@ macro_rules! with_all_bounds {
             }
         }
 
-        fn from_ascii_lowercase<T>(s: &str) -> T where T: $($FromStr)* {
-            if let Some(first_uppercase) = s.bytes().position(|byte| byte >= b'A' && byte <= b'Z') {
-                let mut string = s.to_owned();
-                string[first_uppercase..].make_ascii_lowercase();
-                T::from(string)
-            } else {
-                T::from(s)
-            }
-        }
-
         /// This trait allows to define the parser implementation in regards
         /// of pseudo-classes/elements
         ///
@@ -735,7 +735,8 @@ impl<Impl: SelectorImpl> ToCss for Component<Impl> {
                 write!(CssStringWriter::new(dest), "{}", value)?;
                 dest.write_char('"')?;
                 match case_sensitivity {
-                    CaseSensitivity::CaseSensitive => {},
+                    CaseSensitivity::CaseSensitive |
+                    CaseSensitivity::AsciiCaseInsensitiveIfInHtmlElementInHtmlDocument => {},
                     CaseSensitivity::AsciiCaseInsensitive => dest.write_str(" i")?,
                 }
                 dest.write_char(']')
@@ -790,7 +791,8 @@ impl<Impl: SelectorImpl> ToCss for AttrSelectorWithNamespace<Impl> {
                 write!(CssStringWriter::new(dest), "{}", expected_value)?;
                 dest.write_char('"')?;
                 match case_sensitivity {
-                    CaseSensitivity::CaseSensitive => {},
+                    CaseSensitivity::CaseSensitive |
+                    CaseSensitivity::AsciiCaseInsensitiveIfInHtmlElementInHtmlDocument => {},
                     CaseSensitivity::AsciiCaseInsensitive => dest.write_str(" i")?,
                 }
             },
@@ -1078,7 +1080,7 @@ fn parse_type_selector<P, Impl>(parser: &P, input: &mut CssParser, sequence: &mu
             match local_name {
                 Some(name) => {
                     sequence.push(Component::LocalName(LocalName {
-                        lower_name: from_ascii_lowercase(&name),
+                        lower_name: from_cow_str(to_ascii_lowercase(&name)),
                         name: from_cow_str(name),
                     }))
                 }
@@ -1190,13 +1192,11 @@ fn parse_attribute_selector<P, Impl>(parser: &P, input: &mut CssParser)
 {
     let namespace;
     let local_name;
-    let local_name_lower;
     match parse_qualified_name(parser, input, /* in_attr_selector = */ true)? {
         None => return Err(()),
         Some((_, None)) => unreachable!(),
         Some((ns, Some(ln))) => {
-            local_name_lower = from_ascii_lowercase(&ln);
-            local_name = from_cow_str(ln);
+            local_name = ln;
             namespace = match ns {
                 QNamePrefix::ImplicitNoNamespace |
                 QNamePrefix::ExplicitNoNamespace => {
@@ -1222,6 +1222,8 @@ fn parse_attribute_selector<P, Impl>(parser: &P, input: &mut CssParser)
     match input.next() {
         // [foo]
         Err(()) => {
+            let local_name_lower = from_cow_str(to_ascii_lowercase(&local_name));
+            let local_name = from_cow_str(local_name);
             if let Some(namespace) = namespace {
                 return Ok(Component::AttributeOther(Box::new(AttrSelectorWithNamespace {
                     namespace: namespace,
@@ -1277,8 +1279,22 @@ fn parse_attribute_selector<P, Impl>(parser: &P, input: &mut CssParser)
         _ => return Err(())
     }
 
-    let case_sensitivity = parse_attribute_flags(input)?;
+    let mut case_sensitivity = parse_attribute_flags(input)?;
+
     let value = from_cow_str(value);
+    let local_name_lower;
+    {
+        let local_name_lower_cow = to_ascii_lowercase(&local_name);
+        if let CaseSensitivity::CaseSensitive = case_sensitivity {
+            if include!(concat!(env!("OUT_DIR"), "/ascii_case_insensitive_html_attributes.rs"))
+                .contains(&*local_name_lower_cow)
+            {
+                case_sensitivity = CaseSensitivity::AsciiCaseInsensitiveIfInHtmlElementInHtmlDocument
+            }
+        }
+        local_name_lower = from_cow_str(local_name_lower_cow);
+    }
+    let local_name = from_cow_str(local_name);
     if let Some(namespace) = namespace {
         Ok(Component::AttributeOther(Box::new(AttrSelectorWithNamespace {
             namespace: namespace,
diff --git a/components/style/gecko/snapshot.rs b/components/style/gecko/snapshot.rs
index 3bc1a946c5e..3814eff5810 100644
--- a/components/style/gecko/snapshot.rs
+++ b/components/style/gecko/snapshot.rs
@@ -72,6 +72,10 @@ impl GeckoElementSnapshot {
                     let ignore_case = match case_sensitivity {
                         CaseSensitivity::CaseSensitive => false,
                         CaseSensitivity::AsciiCaseInsensitive => true,
+                        CaseSensitivity::AsciiCaseInsensitiveIfInHtmlElementInHtmlDocument => {
+                            unreachable!("selectors/matching.rs should have \
+                                          called case_sensitivity.to_definite()");
+                        }
                     };
                     // FIXME: case sensitivity for operators other than Equal
                     match operator {
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index 3d8ab270658..3df3381d804 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -1162,6 +1162,10 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
                     let ignore_case = match case_sensitivity {
                         CaseSensitivity::CaseSensitive => false,
                         CaseSensitivity::AsciiCaseInsensitive => true,
+                        CaseSensitivity::AsciiCaseInsensitiveIfInHtmlElementInHtmlDocument => {
+                            unreachable!("selectors/matching.rs should have \
+                                          called case_sensitivity.to_definite()");
+                        }
                     };
                     // FIXME: case sensitivity for operators other than Equal
                     match operator {
diff --git a/python/tidy/servo_tidy/tidy.py b/python/tidy/servo_tidy/tidy.py
index b8229e67d96..51e7e69f8d4 100644
--- a/python/tidy/servo_tidy/tidy.py
+++ b/python/tidy/servo_tidy/tidy.py
@@ -447,6 +447,7 @@ def check_rust(file_name, lines):
 
     prev_use = None
     prev_open_brace = False
+    multi_line_string = False
     current_indent = 0
     prev_crate = {}
     prev_mod = {}
@@ -464,6 +465,15 @@ def check_rust(file_name, lines):
         prev_indent = indent
         indent = len(original_line) - len(line)
 
+        # Hack for components/selectors/build.rs
+        if multi_line_string:
+            if line.startswith('"#'):
+                multi_line_string = False
+            else:
+                continue
+        if line.endswith('r#"'):
+            multi_line_string = True
+
         is_attribute = re.search(r"#\[.*\]", line)
         is_comment = re.search(r"^//|^/\*|^\*", line)