Auto merge of #15822 - charlesvdv:unicode-panic, r=emilio

Correct unicode handling for text input

<!-- Please describe your changes on the following line: -->
Allow proprer handling of unicode sequence in text input.

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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #15819

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- [ ] These changes do not require tests because _____

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components/script/dom/htmlinputelement.rs

@@ -1117,7 +1117,7 @@ impl VirtualMethods for HTMLInputElement {
                                     translated_y
                                 );
                                 if let Some(i) = index {
-                                    self.textinput.borrow_mut().edit_point.index = i as usize;
+                                    self.textinput.borrow_mut().set_edit_point_index(i as usize);
                                     // trigger redraw
                                     self.upcast::<Node>().dirty(NodeDamage::OtherNodeDamage);
                                     event.PreventDefault();