Makes setting negative values to maxLength throw an IndexSize exception

components/script/dom/element.rs

@@ -1109,7 +1109,10 @@ impl Element {
         }
     }
 
-    // TODO: set_int_attribute(...)
+    pub fn set_int_attribute(&self, local_name: &Atom, value: i32) {
+        assert!(&**local_name == local_name.to_ascii_lowercase());
+        self.set_attribute(local_name, AttrValue::Int(DOMString::from(value.to_string()), value));
+    }
 
     pub fn get_uint_attribute(&self, local_name: &Atom, default: u32) -> u32 {
         assert!(local_name.chars().all(|ch| !ch.is_ascii() || ch.to_ascii_lowercase() == ch));

components/script/dom/htmlinputelement.rs

@@ -8,8 +8,8 @@ use dom::attr::{Attr, AttrValue};
 use dom::bindings::cell::DOMRefCell;
 use dom::bindings::codegen::Bindings::AttrBinding::AttrMethods;
 use dom::bindings::codegen::Bindings::EventBinding::EventMethods;
-use dom::bindings::codegen::Bindings::HTMLInputElementBinding::HTMLInputElementMethods;
 use dom::bindings::codegen::Bindings::HTMLInputElementBinding;
+use dom::bindings::codegen::Bindings::HTMLInputElementBinding::HTMLInputElementMethods;
 use dom::bindings::codegen::Bindings::KeyboardEventBinding::KeyboardEventMethods;
 use dom::bindings::global::GlobalRef;
 use dom::bindings::inheritance::Castable;
@@ -104,7 +104,7 @@ impl InputActivationState {
 }
 
 static DEFAULT_INPUT_SIZE: u32 = 20;
-static DEFAULT_MAX_LENGTH : i32 = -1;
+static DEFAULT_MAX_LENGTH: i32 = -1;
 
 impl HTMLInputElement {
     fn new_inherited(localName: DOMString, prefix: Option<DOMString>, document: &Document) -> HTMLInputElement {
@@ -344,15 +344,7 @@ impl HTMLInputElementMethods for HTMLInputElement {
     make_int_getter!(MaxLength, "maxlength", DEFAULT_MAX_LENGTH);
 
     // https://html.spec.whatwg.org/multipage/#dom-input-maxlength
-    fn SetMaxLength(&self, val: i32) {
-        self.maxlength.set(val);
-
-        if val >= 0 {
-            self.textinput.borrow_mut().max_length = Some(val as usize)
-        } else {
-            self.textinput.borrow_mut().max_length = None
-        }
-    }
+    make_limited_int_setter!(SetMaxLength, "maxlength", DEFAULT_MAX_LENGTH);
 
     // https://html.spec.whatwg.org/multipage/#dom-input-indeterminate
     fn Indeterminate(&self) -> bool {

components/script/dom/macros.rs

@@ -26,6 +26,26 @@ macro_rules! make_bool_getter(
     );
 );
 
+#[macro_export]
+macro_rules! make_limited_int_setter(
+    ($attr:ident, $htmlname:tt, $default:expr) => (
+        fn $attr(&self, value: i32) -> $crate::dom::bindings::error::ErrorResult {
+            use dom::bindings::inheritance::Castable;
+            use dom::element::Element;
+
+            let value = if value < 0 {
+                return Err($crate::dom::bindings::error::Error::IndexSize);
+            } else {
+                value
+            };
+
+            let element = self.upcast::<Element>();
+            element.set_int_attribute(&atom!($htmlname), value);
+            Ok(())
+        }
+    );
+);
+
 #[macro_export]
 macro_rules! make_int_getter(
     ($attr:ident, $htmlname:tt, $default:expr) => (

components/script/dom/webidls/HTMLInputElement.webidl

@@ -25,6 +25,7 @@ interface HTMLInputElement : HTMLElement {
   //         attribute DOMString inputMode;
   //readonly attribute HTMLElement? list;
   //         attribute DOMString max;
+          [SetterThrows]
           attribute long maxLength;
   //         attribute DOMString min;
   //         attribute long minLength;

components/style/attr.rs

@@ -5,8 +5,8 @@
 use cssparser::RGBA;
 use std::ops::Deref;
 use string_cache::{Atom, Namespace};
-use util::str::{DOMString, LengthOrPercentageOrAuto, parse_integer, parse_unsigned_integer, parse_legacy_color, parse_length};
-use util::str::{split_html_space_chars, str_join};
+use util::str::{DOMString, LengthOrPercentageOrAuto, parse_unsigned_integer, parse_legacy_color, parse_length};
+use util::str::{split_html_space_chars, str_join, parse_integer};
 use values::specified::{Length};
 
 // Duplicated from script::dom::values.
@@ -53,12 +53,22 @@ impl AttrValue {
         AttrValue::UInt(string, result)
     }
 
-    // https://html.spec.whatwg.org/multipage/infrastructure.html#limited-to-only-non-negative-numbers
     pub fn from_i32(string: DOMString, default: i32) -> AttrValue {
         let result = parse_integer(string.chars()).unwrap_or(default);
         AttrValue::Int(string, result)
     }
 
+    // https://html.spec.whatwg.org/multipage/#limited-to-only-non-negative-numbers
+    pub fn from_limited_i32(string: DOMString, default: i32) -> AttrValue {
+        let result = parse_integer(string.chars()).unwrap_or(default);
+
+        if result < 0 {
+            AttrValue::Int(string, default)
+        } else {
+            AttrValue::Int(string, result)
+        }
+    }
+
     // https://html.spec.whatwg.org/multipage/#limited-to-only-non-negative-numbers-greater-than-zero
     pub fn from_limited_u32(string: DOMString, default: u32) -> AttrValue {
         let result = parse_unsigned_integer(string.chars()).unwrap_or(default);

tests/unit/style/attr.rs

@@ -0,0 +1,33 @@
+/* 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/. */
+
+use style::attr::AttrValue;
+use util::str::DOMString;
+
+#[test]
+fn test_from_limited_i32_should_be_default_when_less_than_0() {
+    let value = DOMString::from("-1");
+    match AttrValue::from_limited_i32(value, 0) {
+        AttrValue::Int(_, 0) => (),
+        _ => panic!("expected an IndexSize error")
+    }
+}
+
+#[test]
+fn test_from_limited_i32_should_parse_a_uint_when_value_is_0_or_greater() {
+    match AttrValue::from_limited_i32(DOMString::from("1"), 0) {
+        AttrValue::Int(_, 1) => (),
+        _ => panic!("expected an successful parsing")
+    }
+}
+
+#[test]
+fn test_from_limited_i32_should_keep_parsed_value_when_not_an_int() {
+    match AttrValue::from_limited_i32(DOMString::from("parsed-value"), 0) {
+        AttrValue::Int(p, 0) => {
+            assert_eq!(p, DOMString::from("parsed_value"))
+        },
+        _ => panic!("expected an successful parsing")
+    }
+}

tests/unit/style/lib.rs

@@ -20,6 +20,7 @@ extern crate util;
 #[cfg(test)] mod stylesheets;
 #[cfg(test)] mod media_queries;
 #[cfg(test)] mod viewport;
+#[cfg(test)] mod attr;
 
 #[cfg(test)] mod writing_modes {
     use style::properties::{INITIAL_VALUES, get_writing_mode};