[LightDM] light pam_conv with gtk-greeter

[f.r.o.p at free.fr]

Hi all,

i am using debian stretch lightdm an gtk greeter from current packages. 
I have developed a pam authentication module that provide some kind of 
other factors auth...

so i have pam_unix and pam_mymodule required in pam.d conf file.

The first attempt to login is ok (prompt for password and ask a 
question)
but if the answer to question is nok, i get no other question displayed 
in info_bar after passord prompt.

I would like lightdm-gtk-greeter to sends/prompts me all messages from 
pam module in the info_bar widget of gtk-greeter. But as far as i dig 
the code, i cant see why this is not happening. this is probably 
somewhere in "process_prompts" function as the comment syas, since i can 
see that all conv messages enter the set_message_label function..!!

BTW: If i just use pam_unix i have some kind of the same problem 
(invalid password in info_bar is only displayed the first time, not on 
every failed attempts.)

I know this is related to gtk-greeter and not lightdm, any help will be 
appreciated
Best regards,