Collapsing copyright year lists to ranges

[Joseph S. Myers]

It was recently confirmed for GDB 
<http://sourceware.org/ml/gdb-patches/2012-01/msg00936.html> that it's OK 
to collapse a list of copyright years into a single range (given the 
required README statement about ranges) even if there were gaps in the 
original list.  This is inline with the principle described in 
maintain.texi that you only need to track years when nontrivial changes 
were made to the package as a whole, not which files were changed in each 
year.

When I suggested doing this for glibc, the question was raised about 
whether that ruling applied to all GNU packages and whether the ruling was 
properly documented.  It seems like quite a common issue for packages 
converting to ranges, so documenting in maintain.texi would seem like a 
good idea.

In particular, the rule about adding all years when the whole package was 
changed comes with the caveat "(Here we assume you're using a publicly 
accessible revision control server, so that every revision installed is 
also immediately and automatically published.)".  That's sufficient for 
new years, but what about older ones when the package may not have had 
public version control (or may have had version control that was private 
at the time with the history later made public)?  Could a rule for 
collapsing to ranges be documented that makes it clear when in such cases 
it's OK to use a range even though the years previously listed in the file 
had some intermediate years missing?

-- 
Joseph S. Myers
address@hidden