Comment 2 for bug 221065

Created an attachment (id=2510)
Compose cache patch

This is the compose cache itself.

The parsed compose tables are stored in /var/X11R6/compose-cache/ (global
cache) or ~/.compose-cache/ (local cache), respectively. Files in the local
cache expire once per day. File dates are compared with the compose table
source files as well. suid and sgid programs are not allowed to use the
local cache.

Caches currently depend on the used locale (more exactly: on the encoding),
but this isn't respected in the cache file format. This has to be changed.
So at least for global cache files, only UTF8 compose files should be
considered.

For user caches this is less problematic as clashes might only occure if the
user
a) has created a .compose-cache
b) uses different locales at the same time
c) these locales use the same compose table
d) parsing of the compose table differs for the used
   locales

Issues to be discussed:

- The per-user cache directory ~/.compose-cache/ is not created if it does
  not exist. In this case non-system compose tables are not cached at all.
  Should it be created automatically if it does not exist?
  I personally doubt this is really usefull.