Dear Maintainer,

* What led up to the situation?

A recent u-u upgrade left file

  /etc/apt/apt.conf.d/50unattended-upgrades.ucf-dist

and I got curious whether APT would properly ignore that.

* What exactly did you do (or not do) that was effective (or
  ineffective)?

Checked the man page apt.conf(5), which says:

  The  Ignore-Files-Silently  list  can  be  used to specify which files APT
  should silently ignore while parsing the files in  the  fragment  directo‐
  ries.   Per  default  a  file  which  ends  with  .disabled,  ~,  .bak  or
  .dpkg-[a-z]+ is silently ignored. As seen in the last default value  these
  patterns can use regular expression syntax.

So according to the man page, the *.ucf-dist file would *not* be ignored.
However, "apt-config dump" shows that the default value of that variable
comprises

  Dir::Ignore-Files-Silently:: "\.ucf-[a-z]+$";

so all is well.

Probably the man page should be updated, and if only to mention that other
files are ignored as well, and that "apt-config dump" could be used to
get the complete truth.

Thanks!