I noticed that on Ubuntu 20.04, some dead key combinations act differently than expected. For instance, dead acute followed by c produces ç, not ć as one might expect.
I have found the keyboard layout definitions at https://gitlab.freedesktop.org/xkeyboard-config/xkeyboard-config/ (and submitted some merge requests for unrelated changes), but could not find any definitions for dead key combinations in that repo.
These combinations appear to be global (i.e. not bound to a specific layout), as the dead acute behaves the same way on different layouts, e.g. de(deadtilde) and lt(us).
Where are the definitions for the dead key mappings on the system? Where is the upstream source repository?
xorgandutilunderneath, but nocompose-tablesunderneath... – user149408 Jul 31 '21 at 23:13libx11-data. As far as I can tell, upstream seems to be at https://gitlab.freedesktop.org/xorg/lib/libx11, and the compose map foriso8859-1is at https://gitlab.freedesktop.org/xorg/lib/libx11/-/blob/master/nls/iso8859-1/Compose.pre. Note that not every locale seems to be present in the repo. – user149408 Jul 31 '21 at 23:21