dh_gencontrol: Fix uninitialized value warning

Regression introduced in commit
6d5f3b79c743ee8b466813ea3e62b4d492fc598c.

Signed-off-by: Niels Thykier <niels@thykier.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/dh_gencontrol b/dh_gencontrol
index 22891683..b65ee595 100755
--- a/dh_gencontrol
+++ b/dh_gencontrol
@@ -196,6 +196,7 @@ sub read_dbgsym_migration {
 sub read_dbgsym_build_ids {
 	my $res = read_dbgsym_file('dbgsym-build-ids', @_);
 	my (%seen, @unique);
+	return '' if not defined($res);
 	for my $id (split(' ', $res)) {
 		next if $seen{$id}++;
 		push(@unique, $id);