[interchange] Also look in the next-highest directory when detecting VCS; add SVN

[David Christensen]

commit da07bbc37a7d92851c7ffa597313c383653e108e
Author: David Christensen <david at endpoint.com>
Date:   Thu Dec 7 11:05:13 2017 -0600

    Also look in the next-highest directory when detecting VCS; add SVN

 Makefile.PL |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)
---
diff --git a/Makefile.PL b/Makefile.PL
index 81d513a..4a9181d 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -457,7 +457,7 @@ EOF
 
 		# install share/ files from MANIFEST
 		chomp(my @sharefiles = grep m:^share/:, @files);
-		$HaveSCCS = (-d "$realdir/.git" or -d "$realdir/CVS" or -d "$realdir/RCS") ? 1 : 0;
+		$HaveSCCS = detect_vcs($realdir);
 		install_file('.', $realdir, $_) for @sharefiles;
 		# install code/ files from MANIFEST
 		chomp(my @codefiles = grep m:^code/:, @files);
@@ -718,6 +718,15 @@ EOF
     return \%X;
 }
 
+sub detect_vcs {
+    my $realdir = shift;
+
+    for my $dir ( qw(.git .svn CVS RCS) ) {
+        return 1 if -d "$realdir/$_" or -d "$realdir/../$_";
+    }
+    return 0;
+}
+
 sub get_dist_version {
 	my $vers = $VERSION;
 	my $is_stable;