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Date: Tue, 14 Apr 2015 23:05:31 -0400
From: Mike Frysinger <vapier@gentoo.org>
To: zsh-workers@zsh.org
Subject: broken parsing with $((`:`))
Message-ID: <20150415030531.GA8187@vapier>
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looks like zsh doesn't correctly parse this:
$ zsh -c 'echo $((`:`))'
zsh:1: bad math expression: illegal character: \M-]

a little whitespace makes it happy:
$ zsh -c 'echo $(( `:`))'
0
$ zsh -c 'echo $((`:` ))'
0

same for $():
$ zsh -c 'echo $(($(:)))'
zsh:1: bad math expression: illegal character: \M-]
$ zsh -c 'echo $(( $(:)))'
0
$ zsh -c 'echo $(($(:) ))'
0

looks like it's related to the subshell not outputting anything.
if you use 'echo 0' instead of ':', it works out.

$ zsh --version
zsh 5.0.7 (x86_64-pc-linux-gnu)
-mike

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