test command parsing and dispatch

  $ hg init a

  $ cd a

Redundant options used to crash (issue436):

  $ hg -v log -v

  $ hg -v log -v x

  $ echo a > a

  $ hg ci -Ama

  adding a

Missing arg:

  $ hg cat

  hg cat: invalid arguments

  hg cat [OPTION]... FILE...

  output the current or given revision of files

  options ([+] can be repeated):

   -o --output FORMAT       print output to file with formatted name

   -r --rev REV             print the given revision

      --decode              apply any matching decode filter

   -I --include PATTERN [+] include names matching the given patterns

   -X --exclude PATTERN [+] exclude names matching the given patterns

  (use 'hg cat -h' to show more help)

  [255]

Missing parameter for early option:

  $ hg log -R 2>&1 | grep 'hg log'

  hg log: option -R requires argument

  hg log [OPTION]... [FILE]

  (use 'hg log -h' to show more help)

  $ hg log -R -- 2>&1 | grep 'hg log'

  hg log: option -R requires argument

  hg log [OPTION]... [FILE]

  (use 'hg log -h' to show more help)

[defaults]

  $ hg cat a

  a

  $ cat >> $HGRCPATH <<EOF

  > [defaults]

  > cat = -r null

  > EOF

  $ hg cat a

  a: no such file in rev 000000000000

  [1]

  $ cd "$TESTTMP"

OSError "No such file or directory" / "The system cannot find the path

specified" should include filename even when it is empty

  $ hg -R a archive ''

  abort: *: '' (glob)

  [255]

#if no-outer-repo

No repo:

  $ hg cat

  abort: no repository found in '$TESTTMP' (.hg not found)!

  [255]

#endif

#if rmcwd

Current directory removed:

  $ mkdir $TESTTMP/repo1

  $ cd $TESTTMP/repo1

  $ rm -rf $TESTTMP/repo1

The output could be one of the following and something else:

 chg: abort: failed to getcwd (errno = *) (glob)

 abort: error getting current working directory: * (glob)

 sh: 0: getcwd() failed: No such file or directory

Since the exact behavior depends on the shell, only check it returns non-zero.

  $ HGDEMANDIMPORT=disable hg version -q 2>/dev/null || false

  [1]

#endif