Single French quotation marks count as two characters
All quotation mark characters are counted as one character except single French quotation marks (Codepoints U+2039 und U+203A, ‹ and ›).
Expected behavior
Single French quotation marks should be counted as one charater, as are normal French quotation marks.
Actual behavior
Single French quotation marks are counted as two characters, as they are not included in the range of quotation mark characters.
Steps to reproduce the behavior
In Twitter: Enter "‹" or "›" and the remaining character count decreases by two instead of one.
In the code: twitter-text/config/v3.json, line 26 defines the end of the block as 8247, single French quotation marks are at 8249 and 8250 (with 8248 being Caret).
Solution
Set "end" in line 26 of twitter-text/config/v3.json to 8250 (accepting to count Caret sign as character with length one, too).
That sounds like a reasonable solution, but I'll need to check in with some others to confirm. Thanks for raising this! We'll look into it.
It took me 3 minutes to get over the term french quotation mark