Hashtags continue through characters at which they should stop
Currently, the number of characters which mark the end of a hashtag in Hubzilla is rather small. There are some characters at which hashtags should stop, but don't.
Hashtags stop at
- blank space
- non-breaking space
- single full stop
- comma
- colon
- semicolon
- question mark
- "typewriter" quotation mark
So far, so good. But they continue through characters such as
- narrow non-breaking space
- zero-width non-breaking space (which renders the trick of only making part of a word a hashtag impossible)
- multiple dots except for the last one
- exclamation mark
- "typewriter" apostrophe (probably non-standard)
- "correct" apostrophe and quotation marks („ “ ” ‚ ‘ ’ « » ‹ ›)
- plus (can be used as a feature for hashtags like #LGBTQIA+, but non-standard and not supported by ActivityPub-based projects)
- dash (may be useful, too, but non-standard again)
- asterisk (useful for tagging Diaspora*, but probably non-standard)
- slash (useful for tagging /kbin, but probably non-standard)
- backslash
- pipe (may be intentional, I don't know)
- all kinds of parentheses, opening as well as closing (when a piece of text between two parentheses ends with a hashtag, the closing parenthesys becomes part of the hashtag)