Bug#805000: /usr/bin/gksudo: Started applications hang

[Ph. Marek]

Package: gksu
Version: 2.0.2-9
Severity: important
File: /usr/bin/gksudo

Related to https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=599233, but 
that's a "wishlist" item, while this here is a bug.


gksudo not only swallows the stderr output, it even makes the program hang 
if there's too much (a pipe full, ie. 64kB) of output:


This here:

    # gksudo -- perl -e 'printf STDERR "%500.500s\n", "a" for 0 .. 100'

just gets eaten, but

    # gksudo -- perl -e 'printf STDERR "%500.500s\n", "a" for 0 .. 1000'

will hang indefinitely.

I could rescue my long-running program by emptying the pipe via 

    # sudo cat /proc/$PID_OF_SUDO_BELOW_GKSUDO/fd/2

but that's unacceptable.



-- System Information:
Debian Release: stretch/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'unstable'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 4.2.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=de_AT.UTF-8, LC_CTYPE=de_AT.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages gksu depends on:
ii  gconf-service             3.2.6-3
ii  libatk1.0-0               2.18.0-1
ii  libc6                     2.19-22
ii  libcairo2                 1.14.4-1
ii  libfontconfig1            2.11.0-6.3
ii  libfreetype6              2.6-2
ii  libgconf-2-4              3.2.6-3
ii  libgdk-pixbuf2.0-0        2.32.1-1
ii  libgksu2-0                2.0.13~pre1-8+b1
ii  libglib2.0-0              2.46.1-2
ii  libgnome-keyring0         3.12.0-1+b1
ii  libgtk2.0-0               2.24.28-1
ii  libpango-1.0-0            1.38.1-1
ii  libpangocairo-1.0-0       1.38.1-1
ii  libpangoft2-1.0-0         1.38.1-1
ii  libstartup-notification0  0.12-4
ii  sudo                      1.8.12-1

Versions of packages gksu recommends:
ii  gnome-keyring  3.18.2-1

gksu suggests no packages.

-- no debconf information