Bug#746434: apt: new apt breaks a shell script by reading from standard input when it shouldn't

[Michael Vogt <mvo@ubuntu.com>]

On Tue, Apr 29, 2014 at 10:40:52PM +0000, Gianluca Borello wrote:
> Package: apt
> Version: 1.0.2
> Severity: normal

Thanks for your bugeport.
 
> I have an automated installation script that doesn't work anymore on Sid. This is a snippet of code:
> 
> #!/bin/bash
> 
> apt-get -qq -y install iftop
> neverexecuted
> 
> If executed by piping it to bash, the very first time (when the package is not installed), I get:
[..]

I can reproduce this and bisected it to commit 872816. The attached
diff fixes it for me, would be great if you could confirm.


Cheers,
 Michael

diff --git a/apt-pkg/deb/dpkgpm.cc b/apt-pkg/deb/dpkgpm.cc
index 959d064..bc86258 100644
--- a/apt-pkg/deb/dpkgpm.cc
+++ b/apt-pkg/deb/dpkgpm.cc
@@ -1239,9 +1239,9 @@ bool pkgDPkgPM::Go(int OutStatusFd)
       // if tcgetattr does not return zero there was a error
       // and we do not do any pty magic
       _error->PushToStack();
-      if (tcgetattr(STDOUT_FILENO, &tt) == 0)
+      if (tcgetattr(STDIN_FILENO, &tt) == 0)
       {
-	 ioctl(0, TIOCGWINSZ, (char *)&win);
+	 ioctl(STDIN_FILENO, TIOCGWINSZ, (char *)&win);
 	 if (openpty(&master, &slave, NULL, &tt, &win) < 0)
 	 {
 	    _error->Errno("openpty", _("Can not write log (%s)"), _("Is /dev/pts mounted?"));