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.
$ hg init repo
$ cd repo
$ touch foo
$ hg ci -Am 'add foo'
adding foo
$ hg up -C null
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
this should be stored as a delta against rev 0
$ echo foo bar baz > foo
$ hg ci -Am 'add foo again'
adding foo
created new head
$ hg debugindex foo
rev offset length ..... linkrev nodeid p1 p2 (re)
0 0 0 ..... 0 b80de5d13875 000000000000 000000000000 (re)
1 0 13 ..... 1 0376abec49b8 000000000000 000000000000 (re)
$ cd ..