tests/test-issue2137.t

doc: show short description of each commands in generated documents

Before this patch, short description of each commands is not shown in
generated documents (HTML file and UNIX man page). This omitting may
prevent users from understanding about commands.

This patch show it as the 1st paragraph in the help section of each
commands. This style is chosen because:

  - showing it as the section title in "command - short desc" style
    disallows referencing by "#command" in HTML file: in "en" locale,
    hyphen concatenated title is used as the section ID in HTML file
    for this style

  - showing it as the 1st paragraph in "command - short desc" style
    seems to be redundant: "command" appears also just before as the
    section title

  - showing it just after synopsis like "hg help command" seems not to
    be reasonable in UNIX man page

This patch just writes short description ("d['desc'][0]") before "::",
because it should be already "strip()"-ed in "get_desc()", or empty
string for the command without description.

http://mercurial.selenic.com/bts/issue2137

Setup:

create a little extension that has 3 side-effects:
1) ensure changelog data is not inlined
2) make revlog to use lazyparser
3) test that repo.lookup() works
1 and 2 are preconditions for the bug; 3 is the bug.

  $ cat > commitwrapper.py <<EOF
  > from mercurial import extensions, node, revlog
  > 
  > def reposetup(ui, repo):
  >     class wraprepo(repo.__class__):
  >         def commit(self, *args, **kwargs):
  >             result = super(wraprepo, self).commit(*args, **kwargs)
  >             tip1 = node.short(repo.changelog.tip())
  >             tip2 = node.short(repo.lookup(tip1))
  >             assert tip1 == tip2
  >             ui.write('new tip: %s\n' % tip1)
  >             return result
  >     repo.__class__ = wraprepo
  > 
  > def extsetup(ui):
  >     revlog._maxinline = 8             # split out 00changelog.d early
  >     revlog._prereadsize = 8           # use revlog.lazyparser
  > EOF

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > commitwrapper = `pwd`/commitwrapper.py
  > EOF

  $ hg init repo1
  $ cd repo1
  $ echo a > a
  $ hg commit -A -m'add a with a long commit message to make the changelog a bit bigger'
  adding a
  new tip: 553596fad57b

Test that new changesets are visible to repo.lookup():

  $ echo a >> a
  $ hg commit -m'one more commit to demonstrate the bug'
  new tip: 799ae3599e0e

  $ hg tip
  changeset:   1:799ae3599e0e
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     one more commit to demonstrate the bug
  

  $ cd ..