Fix longstanding bug (chdir to nonexistent dirs).

In test, set up the post-commit hook for more realism (and bugs!).
To make wrappers work in test, set PERL5LIB, and allow the wrappee's
path to be overridden. Meta-test that post-commit is really hooked
up by verifying that content is getting generated in destdir.

About the longstanding bug, which as far as I know was harmless:
CVS can't operate outside a srcdir, so we're always setting $CWD.
"local $CWD" restores the previous value when we go out of scope.
Usually that's correct. But if we're removing the last file from a
directory, the post-commit hook will exec in a working directory
that's about to not exist (CVS will prune it).

The fix: chdir() manually in cvs_runcvs(), so we can selectively
not chdir() back.

2 files changed, 14 insertions, 2 deletions

diff --git a/IkiWiki/Plugin/cvs.pm b/IkiWiki/Plugin/cvs.pm
index 759ea1c23..bccab3159 100644
--- a/IkiWiki/Plugin/cvs.pm
+++ b/IkiWiki/Plugin/cvs.pm
@@ -502,7 +502,16 @@ sub cvs_runcvs(@) {
 	my @cmd = @_;
 	unshift @cmd, 'cvs', '-Q';
 
-	local $CWD = $config{srcdir};
+	# CVS can't operate outside a srcdir, so we're always setting $CWD.
+	# "local $CWD" restores the previous value when we go out of scope.
+	# Usually that's correct. But if we're removing the last file from
+	# a directory, the post-commit hook will exec in a working directory
+	# that's about to not exist (CVS will prune it).
+	#
+	# chdir() manually here, so we can selectively not chdir() back.
+
+	my $oldcwd = $CWD;
+	chdir($config{srcdir});
 
 	eval q{
 		use IPC::Open3;
@@ -530,6 +539,8 @@ sub cvs_runcvs(@) {
 	print STDOUT $cvsout;
 	print STDERR $cvserr;
 
+	chdir($oldcwd) if -d $oldcwd;
+
 	return ($ret == 0) ? 1 : 0;
 }
 
diff --git a/IkiWiki/Wrapper.pm b/IkiWiki/Wrapper.pm
index 06be36dfc..84b4b5a2f 100644
--- a/IkiWiki/Wrapper.pm
+++ b/IkiWiki/Wrapper.pm
@@ -28,10 +28,11 @@ sub gen_wrappers () {
 	%config=(%origconfig);
 }
 
+our $program_to_wrap = $0;
 sub gen_wrapper () {
 	$config{srcdir}=File::Spec->rel2abs($config{srcdir});
 	$config{destdir}=File::Spec->rel2abs($config{destdir});
-	my $this=File::Spec->rel2abs($0);
+	my $this=File::Spec->rel2abs($program_to_wrap);
 	if (! -x $this) {
 		error(sprintf(gettext("%s doesn't seem to be executable"), $this));
 	}