view tests/test-parseindex.t @ 16853:7863ff383894

help: format command and option list help using RST

This patch changes the function which generates help text about commands and
options to use RST formatting. Tables describing options have been formatted
using RST table markup for some time already, so their appearance does not
change. Command lists, however, change appearance.

To format non-verbose command lists, RST field list markup was chosen, because
it resembles the old format:

<http://docutils.sourceforge.net/docs/user/rst/quickref.html#field-lists>

In the old (hand-coded) format of non-verbose command lists, the left column is
12 characters wide. Our minirst implementation formats field lists with a left
column 14 characters wide, so this patch changes the appearance of help output
correspondingly:

<http://markmail.org/message/krl4cxopsnii7s6z?q=mercurial+reinert+from:%22Olav+Reinert%22&page=2>

The minirst markup most closely resembling the old verbose command lists is
definition lists. But using it would cause a blank line to be inserted between
each command definition, making the output excessively long, and no more
useful than before. To avoid this, I chose to use field lists also for verbose
command help, resulting in output like this example:

 add           add the specified files on the next commit
 annotate, blame
               show changeset information by line for each file
 clone         make a copy of an existing repository
 commit, ci    commit the specified files or all outstanding changes
 diff          diff repository (or selected files)
 export        dump the header and diffs for one or more changesets
 forget        forget the specified files on the next commit
 init          create a new repository in the given directory
 log, history  show revision history of entire repository or files
 merge         merge working directory with another revision
 phase         set or show the current phase name
 pull          pull changes from the specified source
 push          push changes to the specified destination
 qdiff         diff of the current patch and subsequent modifications
 qinit         init a new queue repository (DEPRECATED)
 qnew          create a new patch
 qpop          pop the current patch off the stack
 qpush         push the next patch onto the stack
 qrefresh      update the current patch
 remove, rm    remove the specified files on the next commit
 serve         start stand-alone webserver
 status, st    show changed files in the working directory
 summary, sum  summarize working directory state
 update, up, checkout, co
               update working directory (or switch revisions)

This change is a move towards generating all help text as a list of strings
marked up with RST.

revlog.parseindex must be able to parse the index file even if
an index entry is split between two 64k blocks.  The ideal test
would be to create an index file with inline data where
64k < size < 64k + 64 (64k is the size of the read buffer, 64 is
the size of an index entry) and with an index entry starting right
before the 64k block boundary, and try to read it.
We approximate that by reducing the read buffer to 1 byte.

  $ hg init a
  $ cd a
  $ echo abc > foo
  $ hg add foo
  $ hg commit -m 'add foo'
  $ echo >> foo
  $ hg commit -m 'change foo'
  $ hg log -r 0:
  changeset:   0:7c31755bf9b5
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add foo
  
  changeset:   1:26333235a41c
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change foo
  
  $ cat >> test.py << EOF
  > from mercurial import changelog, scmutil
  > from mercurial.node import *
  > 
  > class singlebyteread(object):
  >     def __init__(self, real):
  >         self.real = real
  > 
  >     def read(self, size=-1):
  >         if size == 65536:
  >             size = 1
  >         return self.real.read(size)
  > 
  >     def __getattr__(self, key):
  >         return getattr(self.real, key)
  > 
  > def opener(*args):
  >     o = scmutil.opener(*args)
  >     def wrapper(*a):
  >         f = o(*a)
  >         return singlebyteread(f)
  >     return wrapper
  > 
  > cl = changelog.changelog(opener('.hg/store'))
  > print len(cl), 'revisions:'
  > for r in cl:
  >     print short(cl.node(r))
  > EOF
  $ python test.py
  2 revisions:
  7c31755bf9b5
  26333235a41c