templatekw: choose {latesttag} by len(changes), not date (issue5659) As Augie reported in the bug, the current heuristic of choosing the best tag of a merge commit by taking the one with newest tag (in terms of tagging date) currently fails in the Mercurial repo itself. Copying the example from Yuya: $ hg glog -T '{node|short} {latesttag}+{latesttagdistance}\n' \ -r '4.2.3: & (merge() + parents(merge()) + tag())' o 02a745c20121 4.2.3+5 |\ | o 86aca74a063b 4.2.3+4 | |\ | | o e6d8ee3c9ec3 4.3-rc+109 | | | | | ~ o | a3ce07e2dde5 4.3.1+2 : | o | 3fee7f7d2da0 4.3.1+0 |/ o 98e990bb7330 4.2.3+3 |\ | ~ o 506d7e48fbe6 4.2.3+2 : o 943c91326b23 4.2.3+0 | ~ It seems to me like the best choice is the tag with the smallest number of changes since it (across all paths, not the longest single path). So that's what this patch does, even though it's costly. Best-of-5 timings for Yuya's command above shows a slowdown from 1.293s to 1.610s. We can optimize it later. Differential Revision: https://phab.mercurial-scm.org/D447