Bug#809148: apt: "apt update" occassionally shows insanely high download rates like e.g. "2953 PB/s 0s" or "3006 PB/s 0s"

[Axel Beckert <abe@debian.org>]

Package: apt
Version: 1.1.6
Severity: minor

Hi,

on a mobile connection with around 25% to 30% packet loss, "apt update"
occassionally stalls and either before or after stalling (don't know for
sure -- but not during stalled downloads, then it shows nothing instead)
it shows "2953 PB/s 0s", "3006 PB/s 0s" (3 Exabytes per second!) or
similar insanely high download rates on the bottom right of the
terminal.

This looks like some divison by zero or maybe even integer overflow or
so to me as the common rates on this connection are between a few bytes
and a few hundred kilobytes per second.

Some information about the connection gathered by noping:

│ 699 packets transmitted, 520 received, 25.61% packet loss, time 48750.3ms
│ RTT[ms]: min = 63, median = 81, p(95) = 125, max = 279
│ ▃▃!▂▂▃!▂▂▂▂▃▃▂▃▂▂▆▂▂!▃!▂▂▃▂▂▂▂▃▂▂▂!!▃▂▃▂!!!!▃▃▂!!!▂▃▂▃!!▂!▂!▃▂▃▃!!▂▂▂▃!▃▃▂▃▃▂▂▂▂▂▂▂!!▃▂▂!▂!▂!▂▂▃!!▂▃▂!▃▃!▂▂▂▂▂!▂!▂▃▂▂▃▃!▂▂!▂▂▃!!▃!!▂▃▂▃

The exclamation marks are packet loss.

(Yes, I know that apt 1.1.8 is out, but I wasn't able to update to it
yet. Guess why I'm seeing the output of "apt update" currently. ;-)

-- Package-specific info:

-- (/etc/apt/preferences present, but not submitted) --


-- (/etc/apt/sources.list present, but not submitted) --

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (990, 'unstable'), (600, 'testing'), (500, 'unstable-debug'), (111, 'buildd-unstable'), (111, 'buildd-experimental'), (110, 'experimental'), (1, 'experimental-debug')
Architecture: amd64 (x86_64)

Kernel: Linux 4.3.0-trunk-amd64 (SMP w/4 CPU cores)
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages apt depends on:
ii  adduser                 3.113+nmu3
ii  debian-archive-keyring  2014.3
ii  gnupg                   1.4.20-1
ii  gnupg2                  2.1.10-3
ii  gpgv                    1.4.20-1
ii  libapt-pkg5.0           1.1.6
ii  libc6                   2.21-6
ii  libgcc1                 1:5.3.1-4
ii  libstdc++6              5.3.1-4

apt recommends no packages.

Versions of packages apt suggests:
ii  apt-doc     1.1.6
ii  aptitude    0.7.5-3
ii  dpkg-dev    1.18.4
ii  python-apt  1.1.0~beta1
ii  synaptic    0.82.5
ii  wajig       2.17

-- Configuration Files:
/etc/apt/apt.conf.d/01autoremove changed:
APT
{
  NeverAutoRemove
  {
	"^firmware-linux.*";
	"^linux-firmware$";
  };
  VersionedKernelPackages
  {
	# linux kernels
	"linux-image";
	"linux-headers";
	"linux-image-extra";
	"linux-signed-image";
	# kfreebsd kernels
	"kfreebsd-image";
	"kfreebsd-headers";
	# hurd kernels
	"gnumach-image";
	# (out-of-tree) modules
	".*-modules";
	".*-kernel";
	"linux-backports-modules-.*";
        # tools
        "linux-tools";
  };
  Never-MarkAuto-Sections
  {
  };
  Move-Autobit-Sections
  {
	"oldlibs";
	"contrib/oldlibs";
	"non-free/oldlibs";
	"restricted/oldlibs";
	"universe/oldlibs";
	"multiverse/oldlibs";
  };
};


-- no debconf information