tests/test-update-reverse.t

dispatch: make "_checkshellalias()" invoke "findcmd()" with "strict=True"

Before this patch, shell alias may be executed by abbreviated command
name unexpectedly, even if abbreviated command name matches also
against the command provided by extension.

For example, "rebate" shell alias is executed by "hg reba", even if
rebase extension (= "rebase" command) is enabled. In this case, "hg
reba" should be aborted because of command name ambiguity.

This patch makes "_checkshellalias()" invoke "cmdutil.findcmd()"
always with "strict=True" (default value).

If abbreviated command name matches against only one shell alias even
after loading extensions, such shell alias will be executed via
"_parse()".

This patch doesn't remove "_checkshellalias()" invocation itself,
because it may prevent shell alias from loading extensions uselessly.

  $ hg init

  $ touch a
  $ hg add a
  $ hg commit -m "Added a"

  $ touch main
  $ hg add main
  $ hg commit -m "Added main"
  $ hg checkout 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

'main' should be gone:

  $ ls
  a

  $ touch side1
  $ hg add side1
  $ hg commit -m "Added side1"
  created new head
  $ touch side2
  $ hg add side2
  $ hg commit -m "Added side2"

  $ hg log
  changeset:   3:91ebc10ed028
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added side2
  
  changeset:   2:b932d7dbb1e1
  parent:      0:c2eda428b523
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added side1
  
  changeset:   1:71a760306caf
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added main
  
  changeset:   0:c2eda428b523
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added a
  

  $ hg heads
  changeset:   3:91ebc10ed028
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added side2
  
  changeset:   1:71a760306caf
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added main
  
  $ ls
  a
  side1
  side2

  $ hg update --debug -C 1
  resolving manifests
   branchmerge: False, force: True, partial: False
   ancestor: 91ebc10ed028+, local: 91ebc10ed028+, remote: 71a760306caf
   side1: other deleted -> r
   side2: other deleted -> r
   main: remote created -> g
  removing side1
  removing side2
  updating: side2 2/3 files (66.67%)
  getting main
  updating: main 3/3 files (100.00%)
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved

  $ ls
  a
  main