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:

   -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

  [+] marked option can be specified multiple times

  use "hg help cat" to show the full help text

  [255]

[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"

  $ hg -R a archive ''

  [255]

#if no-outer-repo

No repo:

  $ hg cat

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

  [255]

#endif