Handle cases where selection API doesn't apply

The selection API only applies to certain <input> types:

https://html.spec.whatwg.org/multipage/#do-not-apply

This commit ensures that we handle that correctly.

Some notes:

1. TextControl::set_dom_selection_direction now calls
   set_selection_range(), which means that setting selectionDirection will
   now fire a selection event, as it should per the spec.

2. There is a test for the firing of the select event in
   tests/wpt/web-platform-tests/html/semantics/forms/textfieldselection/select-event.html,
   however the test did not run due to this syntax error:

   (pid:26017) "ERROR:script::dom::bindings::error: Error at http://web-platform.test:8000/html/semantics/forms/textfieldselection/select-event.html:50:11 missing = in const declaration"

   This happens due to the us of the "for (const foo of ...)" construct.
   Per https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...of
   this should actually work, so it's somewhat unsatisfying to have to
   change the test.

4. If an <input>'s type is unset, it defaults to a text, and the
   selection API applies. Also, if an <input>'s type is set to an
   invalid value, it defaults to a text too. I've expanded the tests
   to account for this second case.

1 files changed, 5 insertions, 3 deletions

diff --git a/components/script/textinput.rs b/components/script/textinput.rs
index 310e0566453..0fe0024a116 100644
--- a/components/script/textinput.rs
+++ b/components/script/textinput.rs
@@ -21,7 +21,7 @@ pub enum Selection {
     NotSelected
 }
 
-#[derive(Clone, Copy, JSTraceable, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, JSTraceable, MallocSizeOf, PartialEq)]
 pub enum SelectionDirection {
     Forward,
     Backward,
@@ -825,7 +825,7 @@ impl<T: ClipboardProvider> TextInput<T> {
         }
     }
 
-    pub fn set_selection_range(&mut self, start: u32, end: u32) {
+    pub fn set_selection_range(&mut self, start: u32, end: u32, direction: SelectionDirection) {
         let mut start = start as usize;
         let mut end = end as usize;
         let text_end = self.get_content().len();
@@ -837,7 +837,9 @@ impl<T: ClipboardProvider> TextInput<T> {
             start = end;
         }
 
-        match self.selection_direction {
+        self.selection_direction = direction;
+
+        match direction {
             SelectionDirection::None |
             SelectionDirection::Forward => {
                 self.selection_begin = Some(self.get_text_point_for_absolute_point(start));