re-search-forward strange match

[Andreas Röhler]

Calling re-search-forward at string "foo1" like below, it matches at 
first char "o".

(re-search-forward "#?[xo]?[a-f0-9]+" nil t 1)foo1

Doesn't the regexp say a possible [xo] must be followed by at least one 
of "a-f0-9"? Where the second "o" is not a part...

Cheers,
Andreas
GNU Emacs 26.1 (build 1, i686-pc-linux-gnu, GTK+ Version 3.14.5) of 
2018-04-10