Trac truncates data at 4-byte UTF-8 characters

[SergeyBiryukov]

See ​#wp18189.

I've noticed that ticket description was truncated. I have the full description in my email notification from 2011, so I've tried to restore it, but it got truncated again.

I guess it's a result of moving to MySQL in #253. According to ​#wp13590, MySQL supports 4-byte UTF-8 characters since version 5.5.

Test: 💩

[SergeyBiryukov]

Another instance in ​#wp31019.

[ocean90]

#1000 was marked as a duplicate.

[nacin]

I've fixed this for core.trac by converting most utf8 columns to utf8mb4. Other Tracs including meta.trac, which all still use SQLite, were unaffected.

I say most because primary key index lengths (innodb_large_prefix is not on) blocked it on the attachment, component, milestone, node_change, ticket_custom, and wiki tables. None of these fields have a pressing (or any) need for four-byte characters in them.

[SergeyBiryukov]

I've tried to restore the description of ​#wp18189 again, and the U+1F4A9 character was replaced with ????.

[nacin]

Test: 💩

[nacin]

Fail, meta.trac is SQLite. I'll do some local testing

[samuelsidler]

Since we switched core trac back to SQLite, is this fixed?

[ocean90]

Yes.