Bug#46537: apt-get update with apt-cdrom broken

[Dwayne Litzenberger <dlitz@cheerful.com>]

Package: apt
Version: 0.3.13
Severity: important

Once I add a CD-ROM using apt-cdrom, apt-get update returns an error.  If
one of the FTP mirrors is down (eg ftp.at.debian.org), the update also fails.

# apt-cdrom add
Using CD-ROM mount point /cdrom/
Unmounting CD-ROM
Please insert a Disc in the drive and press enter 
Mounting CD-ROM
Identifying.. [411dec9b5c0dcae6047ee44b8005a35c-2]
Scanning Disc for index files..  Found 2 package indexes and 0 source indexes.
This Disc is called 'Debian GNU_Linux slink (2.1) 1_4 main binary-i386 section 1
 SAM19990306'
Reading Package Indexes... Done
Wrote 1152 records.
Writing new source list
Source List entries for this Disc are:
deb "cdrom:Debian GNU_Linux slink (2.1) 1_4 main binary-i386 section 1 SAM199903
06/" debian/dists/frozen/contrib/binary-i386/
deb "cdrom:Debian GNU_Linux slink (2.1) 1_4 main binary-i386 section 1 SAM199903
06/" debian/dists/frozen/main/binary-i386/
Repeat this process for the rest of the CDs in your set.
# apt-get update
Hit ftp://ftp.debian.org unstable/main Packages
Hit ftp://ftp.debian.org unstable/main Release
Hit ftp://ftp.debian.org unstable/contrib Packages
Hit ftp://ftp.debian.org unstable/contrib Release
Hit ftp://ftp.debian.org unstable/non-free Packages
Hit ftp://ftp.debian.org unstable/non-free Release
Failed to fetch cdrom:Debian GNU_Linux slink (2.1) 1_4 main binary-i386 section 1 SAM19990306/debian/dists/froz
en/contrib/binary-i386/Packages
  Method gave a blank filename
Failed to fetch cdrom:Debian GNU_Linux slink (2.1) 1_4 main binary-i386 section 1 SAM19990306/debian/dists/froz
en/contrib/binary-i386/Release
  Method gave a blank filename
Failed to fetch cdrom:Debian GNU_Linux slink (2.1) 1_4 main binary-i386 section 1 SAM19990306/debian/dists/froz
en/main/binary-i386/Packages
  Method gave a blank filename
Failed to fetch cdrom:Debian GNU_Linux slink (2.1) 1_4 main binary-i386 section 1 SAM19990306/debian/dists/froz
en/main/binary-i386/Release
  Method gave a blank filename
Reading Package Lists... Done
Building Dependency Tree... Done
E: Some index files failed to download, they have been ignored, or old ones used instead.
# echo $?
100
#


I am using an updated Debian system from unstable, kernel version 2.2.11-ac3,
libc-2.1.2, bash 2.02.1(1)-release on an ix86.

Apt has not worked satisfactorily since 0.3.11 (which now conflicts with
debconf).