tests/test-merge4.t

revset: get revision number of each node from target namespaces

Before this patch, revset predicate "named()" uses each nodes gotten
from target namespaces directly.

This causes problems below:

  - combination of other predicates doesn't work correctly, because
    they assume that revisions are listed up in number

  - "hg log" doesn't show any revisions for "named()" result, because:

    - "changeset_printer" stores formatted output for each revisions
      into dict with revision number (= ctx.rev()) as a key of them

    - "changeset_printer.flush(rev)" writes stored output for
      the specified revision, but

    - "commands.log" invokes it with the node, gotten from "named()"

  - "hg debugrevspec" shows nodes (= may be binary) directly

Difference between revset predicate "tag()" and "named('tags')" in
tests is fixed in subsequent patch.

  $ hg init
  $ echo This is file a1 > a
  $ hg add a
  $ hg commit -m "commit #0"
  $ echo This is file b1 > b
  $ hg add b
  $ hg commit -m "commit #1"
  $ hg update 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo This is file c1 > c
  $ hg add c
  $ hg commit -m "commit #2"
  created new head
  $ hg merge 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ rm b
  $ echo This is file c22 > c

Test hg behaves when committing with a missing file added by a merge

  $ hg commit -m "commit #3"
  abort: cannot commit merge with missing files
  [255]