This is similar to bug 49233.
Some languages or writing systems require combining diacritics.
In theory most characters with diacritics can be input with combining diacritics, for example é (e + combining acute) is equivalent to é (eacute). For some combination only the use of combining diacritics is possible, for exemple ɔ́ (open o + combining acute).
When typing or pasting text with combining diacritics the following occurs:
- the first character after a combining diacritics is duplicated on a new line below the cursor.
- pressing backspace pushes the characters after the first combining diacritics to that line below, the cursor jumps to the end of the newline and the first character that was duplicated jumps behind the cursor as well.
- pressing backspace gets stuck a the combining diacritics, erasing the duplicated character last, after the characters that jumped and the line return but not erasing the combining diacritics and its base character.
For example, typing
```
té
```
is fine.
But typing other characters becomes:
```
tél
l
```
then
```
télévision
l
```
Pressing backspace with the cursor at the end of the first line:
```
té
élvisio
```
with the cursor before the o, but the next backspace will delete the o and the cursor jumps before the i.
The expected result should be the word "télévision" and pressing backspace should delete the character before the cursor or the character cluster before the cursor.