tests: omit -p for external diff via extdiff extension for portability Before this patch, some tests using external "diff" command via extdiff extension fail on Solaris, because "-p" (show which C function each change is in) option isn't supported by system standard "diff" on Solaris, even though extdiff passes it to external "diff" by default. Fortunately, this non-portable option isn't important for (current, at least) tests using external "diff" command via extdiff extension. This patch omits "-p" for external "diff" command via extdiff extension for portability of tests, and adds check-code.py a rule to detect invocation of "diff" with "-p". Newly added check-code.py rule examines only lines generated by external "diff" with "-r", because strict examination might misidentify "hg diff -p" or other complicated lines consisting of "diff" string as wrong one. This patch is a part of making tests using external "diff" portable, and tests below aren't yet portable even after this patch. test-graft.t test-largefiles-update.t test-subrepo-deep-nested-change.t

Testing that hghave does not crash when checking features

  $ hghave --test-features 2>/dev/null

Testing hghave extensibility for third party tools

  $ cat > hghaveaddon.py <<EOF
  > import hghave
  > @hghave.check("custom", "custom hghave feature")
  > def has_custom():
  >     return True
  > EOF

(invocation via run-tests.py)

  $ cat > test-hghaveaddon.t <<EOF
  > #require custom
  >   $ echo foo
  >   foo
  > EOF
  $ run-tests.py $HGTEST_RUN_TESTS_PURE test-hghaveaddon.t
  .
  # Ran 1 tests, 0 skipped, 0 warned, 0 failed.

(invocation via command line)

  $ unset TESTDIR
  $ hghave custom

(terminate with exit code 2 at failure of importing hghaveaddon.py)

  $ rm hghaveaddon.*
  $ cat > hghaveaddon.py <<EOF
  > importing this file should cause syntax error
  > EOF

  $ hghave custom
  failed to import hghaveaddon.py from '.': invalid syntax (hghaveaddon.py, line 1)
  [2]