keyword: restore kwtemplater.restrict at the end of wrapped patch.diff
Before this patch, kwdiff doesn't restore kwtemplater.restrict after
invocation of wrapped patch.diff(). This suppresses keyword expansion
at subsequent filelog.read().
Typical usecase of this issue is "hg cat" after "hg diff" with command
server. In this case, kwtemplater.restrict=True is kept in command
server process even after "hg diff".
To ensure kwtemplater.restrict=True while original patch.diff()
running, this patch makes kwdiff() yield values returned by it,
because it returns generator object.
Strictly speaking, if filelog.read() is invoked before completely
evaluating the result of previous patch.diff(), keyword expansion is
still suppressed, because kwtemplater.restrict isn't restored yet.
But this fixing should be reasonable enough, because patch.diff() is
consumed immediately, AFAIK.
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 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]