From 6712ff48e8dcc89a3d8aee30f7f114322ed19ba9 Mon Sep 17 00:00:00 2001
From: Matt Shin <matthew.shin@metoffice.gov.uk>
Date: Tue, 21 Feb 2017 12:03:33 +0000
Subject: [PATCH] fcm switch: fix Perl warning

This happened on an unexpected usage. A user has checked out an entire
project tree, and then run `fcm switch trunk` on it. Clearly it did not
work, but the added Perl warning was not helpful either.
---
 lib/FCM1/Cm.pm | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/FCM1/Cm.pm b/lib/FCM1/Cm.pm
index c8b5193e..0a1bd9aa 100644
--- a/lib/FCM1/Cm.pm
+++ b/lib/FCM1/Cm.pm
@@ -1794,7 +1794,9 @@ sub _cm_get_source {
         return _cm_err(FCM1::Cm::Exception->INVALID_BRANCH, $source_url);
     }
     $source->url_peg(
-      $source->branch_url() . '/' . $target->subdir() . '@' . $source->pegrev()
+        $source->branch_url()
+        . ($target->subdir() ? '/' . $target->subdir() : q{})
+        . ('@' . $source->pegrev())
     );
     # Ensure that the source and target URLs are in the same project
     if ($source->project_url() ne $target->project_url()) {