tests: make tests with temporary environment setting portable With "dash" (as "/bin/sh" on Debian GNU/Linux), command execution in "ENV=val foo bar" style doesn't work as expect in test script files, if "foo" is user-defined function: it works fine, if "foo" is existing commands like "hg". 09049042ab99 introduced tests for HGPLAIN and HGPLAINEXCEPT into test-revset.t, and all of them are in such style. This patch doesn't: - add explicit unsetting for HGPLAIN and HGPLAINEXCEPT they are already introduced by 09049042ab99 - write assignment and exporting in one line "ENV=val; export ENV" for two or more environment variables in one line causes failure of test-check-code-hg.t: it is recognized as "don't export and assign at once" unfortunately.

http://mercurial.selenic.com/bts/issue612

  $ hg init
  $ mkdir src
  $ echo a > src/a.c
  $ hg ci -Ama
  adding src/a.c

  $ hg mv src source
  moving src/a.c to source/a.c (glob)

  $ hg ci -Ammove

  $ hg co -C 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo new > src/a.c
  $ echo compiled > src/a.o
  $ hg ci -mupdate
  created new head

  $ hg status
  ? src/a.o

  $ hg merge
  merging src/a.c and source/a.c to source/a.c
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg status
  M source/a.c
  R src/a.c
  ? src/a.o