bug#19735: 25.0.50; regression: contrary to documentation etags does not work with compressed files any more; did work in emacs 24.4

[Eli Zaretskii]

> From: Gregor Zattler <grfz@gmx.de>
> Date: Fri, 30 Jan 2015 18:51:25 +0100
> 
> etags from emacs24 in debian jessie:
> GNU Emacs 24.4.1 (i586-pc-linux-gnu, X toolkit, Xaw3d scroll
> bars) of 2014-12-19 on brahms, modified by Debian
> 
> is able to work with e.g.
> /usr/share/emacs/24.4/lisp/dired-aux.el.gz
> 
> while ~/src/emacs/lib-src/etags build from recent source is not:
> 
> $ ~/src/emacs/lib-src/etags /usr/share/emacs/24.4/lisp/dired-aux.el.gz
> /usr/share/emacs/24.4/lisp/dired-aux.el.gz: Invalid argument
> 
> I did a git bisect on the emacs repository, this is the result:
> 
> first bad commit: [ba1ed52f0c2c7fd15fe1feadabfd0af88e19b4c3] Use binary-io 
> module, O_BINARY, and „b“ flag.

Amazingly enough, the "b" flag in 'popen' is not supported on
GNU/Linux, at least some of its versions.

Fixed in commit d10c3ed.

Thanks.