Bug#526661: [aptitude]

[Daniel Burrows <dburrows@debian.org>]

On Wed, Nov 18, 2009 at 04:11:43PM +0100, Julian Andres Klode <jak@debian.org> was heard to say:
> On Wed, Nov 18, 2009 at 06:22:02AM -0800, Daniel Burrows wrote:
> >   *bangs head on desk*
> > 
> >   So here's what we have.  aptitude tries to avoid downloading a new
> > copy of a changelog by instead reusing one that it finds installed on
> > the system.  To do this, it looks up the source package and checks
> > whether any of its binaries are installed, which requires reading in
> > apt's list of source records.  You don't have any source records, so
> > the source record of the package can't be found, so aptitude won't try
> > to use a locally installed changelog (maybe instead it should check for
> > a changelog from the same binary, but it won't).
> > 
> >   Here's the wall-banger: the apt object representing the list of source
> > records emits the error message you're seeing *in its constructor* if
> > you don't have any source records listed in /etc/apt/sources.list.  Even
> > more fun, I don't see any reasonable way (short of duplicating a bunch
> > of apt code) to replicate the test it uses exactly.  I'll implement a
> > quick and dirty workaround, but this is really an apt bug IMO.
> 
> I guess we could move the test code to a function and call this
> function from within the constructor. Then you could just call the
> function and go a different way if it returns false (i.e. if there are
> no deb-src entries).

  Yeah, I think that would be ideal.  As a workaround, I just copied
that little loop at the top of the constructor and I assume there's
a deb-src line if it succeeds:

---- cut here ----
      bool source_lines_exist()
      {
	for (pkgSourceList::const_iterator sourceListIt =
	       apt_source_list->begin();
	     sourceListIt != apt_source_list->end();
	     ++sourceListIt)
	  {
	    // Partly cribbed from srcrecords.cc in apt.
	    std::vector<pkgIndexFile *> *indexes = (*sourceListIt)->GetIndexFiles();
	    for (std::vector<pkgIndexFile *>::const_iterator indexesIt =
		   indexes->begin(); indexesIt != indexes->end(); ++indexesIt)
	      {
		boost::scoped_ptr<pkgSrcRecords::Parser>
		  parser((*indexesIt)->CreateSrcParser());

		if(parser.get() != NULL)
		  return true;
	      }
	  }

	return false;
      }
---- cut here ----

  (sorry if the mail earlier was a little strong -- I got up much
earlier in the morning than I'm used to and that sometimes makes me
a bit cranky :P )

  Daniel