tests/test-merge5.t

fileset: use decorator to mark a function as fileset predicate

Using decorator can localize changes for adding (or removing) a
fileset predicate function in source code.

It is also useful to pick predicates up for specific purpose. For
example, subsequent patches marks predicates as "call status" or "use
existing" via decorator.

To avoid (1) redundancy between "predicate name" and (the beginning
of) help document, and (2) accidental typo of help document, this
patch also makes decorator put predicate declration into the beginning
of help.

  $ hg init
  $ echo This is file a1 > a
  $ echo This is file b1 > b
  $ hg add a b
  $ hg commit -m "commit #0"
  $ echo This is file b22 > b
  $ hg commit -m "comment #1"
  $ hg update 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm b
  $ hg commit -A -m "comment #2"
  removing b
  created new head
  $ hg update 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg update
  abort: not a linear update
  (merge or update --check to force update)
  [255]
  $ rm b
  $ hg update -c
  abort: uncommitted changes
  [255]
  $ hg revert b
  $ hg update -c
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ mv a c

Should abort:

  $ hg update 1
  abort: uncommitted changes
  (commit or update --clean to discard changes)
  [255]
  $ mv c a

Should succeed:

  $ hg update 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved