show: use consistent (and possibly shorter) node lengths `hg show` makes heavy use of shortest() to limit the length of the node hash. For the "stack" and "work" views, you are often looking at multiple lines of similar output for "lines" of work. It is visually appeasing for things to vertically align. A naive use of {shortest(node, N)} could result in variable length nodes and for the first character of the description to vary by a column or two. We implement a function to determine the longest shortest prefix for a set of revisions. The new function is used to determine the printed node length for all `hg show` views. .. feature:: show: use consistent node length in views Our previous shortest node length of 5 was arbitrarily chosen. shortest() already does the work of ensuring that a partial node isn't ambiguous with an integer revision, which is our primary risk of a collision for very short nodes. It should be safe to go with the shortest node possible. Existing code is also optimized to handle nodes as short as 4. So, we decrease the minimum hash length from 5 to 4. We also add a test demonstrating that prefix collisions increase the node length. .. feature:: show: decrease minimum displayed hash length from 5 to 4 Differential Revision: https://phab.mercurial-scm.org/D558

#require killdaemons

= Test the known() protocol function =

Create a test repository:

  $ hg init repo
  $ cd repo
  $ touch a ; hg add a ; hg ci -ma
  $ touch b ; hg add b ; hg ci -mb
  $ touch c ; hg add c ; hg ci -mc
  $ hg log --template '{node}\n'
  991a3460af53952d10ec8a295d3d2cc2e5fa9690
  0e067c57feba1a5694ca4844f05588bb1bf82342
  3903775176ed42b1458a6281db4a0ccf4d9f287a
  $ cd ..

Test locally:

  $ hg debugknown repo 991a3460af53952d10ec8a295d3d2cc2e5fa9690 0e067c57feba1a5694ca4844f05588bb1bf82342 3903775176ed42b1458a6281db4a0ccf4d9f287a
  111
  $ hg debugknown repo 000a3460af53952d10ec8a295d3d2cc2e5fa9690 0e067c57feba1a5694ca4844f05588bb1bf82342 0003775176ed42b1458a6281db4a0ccf4d9f287a
  010
  $ hg debugknown repo
  

Test via HTTP:

  $ hg serve -R repo -p $HGPORT -d --pid-file=hg.pid -E error.log -A access.log
  $ cat hg.pid >> $DAEMON_PIDS
  $ hg debugknown http://localhost:$HGPORT/ 991a3460af53952d10ec8a295d3d2cc2e5fa9690 0e067c57feba1a5694ca4844f05588bb1bf82342 3903775176ed42b1458a6281db4a0ccf4d9f287a
  111
  $ hg debugknown http://localhost:$HGPORT/ 000a3460af53952d10ec8a295d3d2cc2e5fa9690 0e067c57feba1a5694ca4844f05588bb1bf82342 0003775176ed42b1458a6281db4a0ccf4d9f287a
  010
  $ hg debugknown http://localhost:$HGPORT/
  
  $ cat error.log
  $ killdaemons.py