For push display names are interpreted as regex

[erikjohnston]

Specifically, if you specify a display name of [benpa] then that will cause the contains_display_name to match against the regex (^|\W)[benpa](\W|$), which matches any event with the word "a" in it.

This is because we pass the display name straight into _glob_matches and the glob to regex conversion doesn't escape regex characters in the glob. (We also probably don't want to be using display name as a glob)

[benparsons]

But I want this name! I blame @uhoreg for giving the idea!

[uhoreg]

FWIW, I worked around the issue by turning off notifications on "Messages containing my displayname".

[richvdh]

this is disasterous for performance.

[clokep]

Fixed by #7271.