Why DBus errors name cannot contains "_" or "-" in dbus-glib?

[maxprofitisback]

Hi,

Next to 0.84 release of dbus-glib if a name of a GError contains "_" or
"-", this character is squashed (see git commit
9637ed9f0c66982a06048b18ccf983881643e456)

Why an error name like "FAILED_ERROR" will be replaced in "FAILEDERROR" ?

Thanks