fix(keyevent): do not emit default ignorable codepoint

ports/servo/glutin_app/window.rs

@@ -346,8 +346,32 @@ impl Window {
         GlRequest::Specific(Api::OpenGlEs, (3, 0))
     }
 
+    /// Detect if given char is default ignorable in unicode
+    /// http://www.unicode.org/L2/L2002/02368-default-ignorable.pdf
+    fn is_identifier_ignorable(&self, ch: &char) -> bool {
+        match *ch {
+            '\u{0000}'...'\u{0008}' | '\u{000E}'...'\u{001F}' |
+            '\u{007F}'...'\u{0084}' | '\u{0086}'...'\u{009F}' |
+            '\u{06DD}' | '\u{070F}' |
+            '\u{180B}'...'\u{180D}' | '\u{180E}' |
+            '\u{200C}'...'\u{200F}' |
+            '\u{202A}'...'\u{202E}' | '\u{2060}'...'\u{2063}' |
+            '\u{2064}'...'\u{2069}' | '\u{206A}'...'\u{206F}' |
+            '\u{FE00}'...'\u{FE0F}' | '\u{FEFF}' |
+            '\u{FFF0}'...'\u{FFF8}' | '\u{FFF9}'...'\u{FFFB}' |
+            '\u{1D173}'...'\u{1D17A}' | '\u{E0000}' |
+            '\u{E0001}' |
+            '\u{E0002}'...'\u{E001F}' | '\u{E0020}'...'\u{E007F}' |
+            '\u{E0080}'...'\u{E0FFF}' => true,
+            _ => false
+        }
+    }
+
     fn handle_received_character(&self, ch: char) {
         let modifiers = Window::glutin_mods_to_script_mods(self.key_modifiers.get());
+        if self.is_identifier_ignorable(&ch) {
+            return
+        }
         if let Some(last_pressed_key) = self.last_pressed_key.get() {
             let event = WindowEvent::KeyEvent(Some(ch), last_pressed_key, KeyState::Pressed, modifiers);
             self.event_queue.borrow_mut().push(event);