Unexpected result while constructing strings

[Hermann Peifer]

Hello Arnold,

I found this somewhat unexpected result while constructing strings. I am 
not quite sure if this is a bug or rather a feature.

$ gawk-stable/gawk 'BEGIN{a = "str" FS ++c ; print a}' | cat -A
str0$

This works as expected:

$ gawk-stable/gawk 'BEGIN{a = "str" FS c ; print a}' | cat -A
str $

$ gawk-stable/gawk 'BEGIN{a = "str" (FS) ++c ; print a}' | cat -A
str 1$

Hermann