Make specification of CVS module to convert optional.

If we're inside a checked out CVS repository, there is
no need to explicitly specify the module as it is
available in CVS/Repository.
Also read CVS/Root if it's available and -d is not specified.
Finally, explicitly pass root to cvsps as CVS/Root takes
precedence over CVSROOT.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>

Documentation/git-cvsimport-script.txt

@@ -11,7 +11,7 @@ SYNOPSIS
 --------
 'git-cvsimport-script' [ -o <branch-for-HEAD> ] [ -h ] [ -v ]
 			[ -d <CVSROOT> ] [ -p <options-for-cvsps> ]
-			<CVS_module> [ <GIT_repository> ]
+			[ -C <GIT_repository> ] [ <CVS_module> ]
 
 
 DESCRIPTION

git-cvsimport-script

@@ -26,35 +26,53 @@ use POSIX qw(strftime dup2);
 $SIG{'PIPE'}="IGNORE";
 $ENV{'TZ'}="UTC";
 
-our($opt_h,$opt_o,$opt_v,$opt_d,$opt_p);
+our($opt_h,$opt_o,$opt_v,$opt_d,$opt_p,$opt_C);
 
 sub usage() {
 	print STDERR <<END;
 Usage: ${\basename $0}     # fetch/update GIT from CVS
 	   [ -o branch-for-HEAD ] [ -h ] [ -v ] [ -d CVSROOT ]
-       [ -p opts-for-cvsps ]
-       CVS_module [ GIT_repository ]
+       [ -p opts-for-cvsps ] [ -C GIT_repository ]
+       [ CVS_module ]
 END
 	exit(1);
 }
 
-getopts("hqvo:d:p:") or usage();
+getopts("hqvo:d:p:C:") or usage();
 usage if $opt_h;
 
-@ARGV == 1 or @ARGV == 2 or usage();
-
-my($cvs_tree, $git_tree) = @ARGV;
+@ARGV <= 1 or usage();
 
 if($opt_d) {
 	$ENV{"CVSROOT"} = $opt_d;
+} elsif(-f 'CVS/Root') {
+	open my $f, '<', 'CVS/Root' or die 'Failed to open CVS/Root';
+	$opt_d = <$f>;
+	chomp $opt_d;
+	close $f;
+	$ENV{"CVSROOT"} = $opt_d;
 } elsif($ENV{"CVSROOT"}) {
 	$opt_d = $ENV{"CVSROOT"};
 } else {
 	die "CVSROOT needs to be set";
 }
 $opt_o ||= "origin";
+my $git_tree = $opt_C;
 $git_tree ||= ".";
 
+my $cvs_tree;
+if ($#ARGV == 0) {
+	$cvs_tree = $ARGV[0];
+} elsif (-f 'CVS/Repository') {
+	open my $f, '<', 'CVS/Repository' or 
+	    die 'Failed to open CVS/Repository';
+	$cvs_tree = <$f>;
+	chomp $cvs_tree;
+	close $f
+} else {
+	usage();
+}
+
 select(STDERR); $|=1; select(STDOUT);
 
 
@@ -378,7 +396,7 @@ die "Cannot fork: $!\n" unless defined $pid;
 unless($pid) {
 	my @opt;
 	@opt = split(/,/,$opt_p) if defined $opt_p;
-	exec("cvsps",@opt,"-x","-A","--cvs-direct",$cvs_tree);
+	exec("cvsps",@opt,"-x","-A","--cvs-direct",'--root',$opt_d,$cvs_tree);
 	die "Could not start cvsps: $!\n";
 }