tests: test for dispatch on [defaults]: more clearly differing output

Using '-r null' instead of '-v' as the overriden command default.
The latter did not have any effect on output, thus not giving much
indication on whether the modified defaults were really in use or not.

tests/test-dispatch

@@ -1,27 +1,27
 #!/bin/sh
 # test command parsing and dispatch
 
 "$TESTDIR/hghave" no-outer-repo || exit 80
 
 hg init a
 cd a
 echo a > a
 hg ci -Ama
 
 echo "# missing arg"
 hg cat
 
 echo '% [defaults]'
 hg cat a
 cat >> $HGRCPATH <<EOF
 [defaults]
-cat = -v
+cat = -r null
 EOF
 hg cat a
 
 echo '% no repo'
 cd ..
 hg cat
 
 exit 0
 

tests/test-dispatch.out

@@ -1,33 +1,33
 adding a
 # missing arg
 hg cat: invalid arguments
 hg cat [OPTION]... FILE...
 
 output the current or given revision of files
 
     Print the specified files as they were at the given revision. If
     no revision is given, the parent of the working directory is used,
     or tip if no revision is checked out.
 
     Output may be to a file, in which case the name of the file is
     given using a format string. The formatting rules are the same as
     for the export command, with the following additions:
 
     %s   basename of file being printed
     %d   dirname of file being printed, or '.' if in repository root
     %p   root-relative path name of file being printed
 
 options:
 
  -o --output   print output to file with formatted name
  -r --rev      print the given revision
     --decode   apply any matching decode filter
  -I --include  include names matching the given patterns
  -X --exclude  exclude names matching the given patterns
 
 use "hg -v help cat" to show global options
 % [defaults]
 a
-a
+a: No such file in rev 000000000000
 % no repo
 abort: There is no Mercurial repository here (.hg not found)!