possible bug on readline

[Samus_]

hello,  I had this on my shell: fgrep "$(nl_join " templates/
advertiser/campaign* and when tried to perform readline's glob-expand-
word I got some parse errors, I'm not sure if it is a bug or the
expected behaviour because the line isn't functional code however I'm
not sure if that should affect the expansion.

full output:
$ fgrep "$(nl_join " templates/advertiser/campaign*bash: command
substitution: line 21: unexpected EOF while looking for matching `"'
bash: command substitution: line 22: syntax error: unexpected end of
file
bash: command substitution: line 21: unexpected EOF while looking for
matching `"'
bash: command substitution: line 22: syntax error: unexpected end of
file
bash: command substitution: line 21: unexpected EOF while looking for
matching `"'
bash: command substitution: line 22: syntax error: unexpected end of
file
bash: command substitution: line 21: unexpected EOF while looking for
matching `"'
bash: command substitution: line 22: syntax error: unexpected end of
file
bash: command substitution: line 21: unexpected EOF while looking for
matching `"'
bash: command substitution: line 22: syntax error: unexpected end of
file

the original line was: fgrep "$(nl_join templates/advertiser/
campaign*)" -R * --color --include='*.py' but the expansion doesn't
work there so I was trying to get it separately.

$BASH_VERSION is 4.0.35(2)-release and I'm on Arch Linux using the
x86_64 package provided (pkg vers: 4.0.035-1), readline pkg version is
x86_64 6.0.004-1, hardware is AMD Phenom(tm) 8450 Triple-Core
Processor.

to reproduce simply try to glob-expand the following code: "$(" *

ps: bash at gnu.org rejected my email.