Hello together,
i'm having a problem with SY-LANGU in remote function calls.
If i call a RFC from a 3rd-party system i get SY-LANGU with the entry 'D'. That's very strange because i have maintained the language 'E' in my user profile.
So i changed SY-LANGU to 'E' at the beginning of my function module. No good style, i know... 
But deep in the system, there is the following coding:
* translate DESCRIPTION_UC to UPPER CASE.
* that is necessarry to use the field 'description_uc' in search helps
cs_orderadm_h_wrk-description_uc = cs_orderadm_h_wrk-description
SET LOCALE LANGUAGE cs_orderadm_h_wrk-descr_language.
TRANSLATE cs_orderadm_h_wrk-description_uc TO UPPER CASE.
SET LOCALE LANGUAGE space.
This coding sets the language to 'D', again.
I found the following explanation for the part with 'space':
"The special form SET LOCALE LANGUAGE SPACE (or lg contains SPACE) resets the text environment to the language of the active user as specified in the user master record."
I understand the function of this coding, but not the result. If i check SY-UNAME i get my user, so everything works fine.
Do you have any idea about this strange behaviour?
Best regards,
Sascha