tests/test-gendoc.t

revlog: improve delta generation heuristics for generaldelta

Without this change, pulls (and clones) into a generaldelta repository could
generate very inefficient revlogs, the size of which could be at least twice
the original size.

This was caused by the generated delta chains covering too large distances,
causing new chains to be built far too often. This change addresses the
problem by forcing a delta against second parent or against the previous
revision, when the first parent delta is in danger of creating a long chain.

Test document extraction

  $ "$TESTDIR/hghave" docutils || exit 80
  $ HGENCODING=UTF-8
  $ export HGENCODING
  $ for PO in C $TESTDIR/../i18n/*.po; do
  >     LOCALE=`basename $PO .po`
  >     echo
  >     echo "% extracting documentation from $LOCALE"
  >     echo ".. -*- coding: utf-8 -*-" > gendoc-$LOCALE.txt
  >     echo "" >> gendoc-$LOCALE.txt
  >     LC_ALL=$LOCALE python $TESTDIR/../doc/gendoc.py >> gendoc-$LOCALE.txt 2> /dev/null || exit
  > 
  >     # We call runrst without adding "--halt warning" to make it report
  >     # all errors instead of stopping on the first one.
  >     echo "checking for parse errors"
  >     python $TESTDIR/../doc/runrst html gendoc-$LOCALE.txt /dev/null
  > done
  
  % extracting documentation from C
  checking for parse errors
  
  % extracting documentation from da
  checking for parse errors
  
  % extracting documentation from de
  checking for parse errors
  
  % extracting documentation from el
  checking for parse errors
  
  % extracting documentation from fr
  checking for parse errors
  
  % extracting documentation from it
  checking for parse errors
  
  % extracting documentation from ja
  checking for parse errors
  
  % extracting documentation from pt_BR
  checking for parse errors
  
  % extracting documentation from ro
  checking for parse errors
  
  % extracting documentation from sv
  checking for parse errors
  
  % extracting documentation from zh_CN
  checking for parse errors
  
  % extracting documentation from zh_TW
  checking for parse errors