An empty file does not have a positive number of lines.

Make sure that the number of lines read is non-zero before in order to
avoid dumping core.

Reported by:	Wojciech A. Koszek
Pointy hat to:	cperciva

1 files changed, 7 insertions, 0 deletions

diff --git a/usr.sbin/portsnap/make_index/make_index.c b/usr.sbin/portsnap/make_index/make_index.c
index c02bba8b0deb..410b5b7cc45c 100644
--- a/usr.sbin/portsnap/make_index/make_index.c
+++ b/usr.sbin/portsnap/make_index/make_index.c
@@ -411,6 +411,7 @@ printport(PORT * p)
 /*
  * Algorithm:
  * 1. Suck in all the data, splitting into fields.
+ * 1a. If there are no ports, there is no INDEX.
  * 2. Sort the ports according to port directory.
  * 3. Using a binary search, translate each dependency from a
  * port directory name into a pointer to a port.
@@ -470,6 +471,12 @@ main(int argc, char *argv[])
 		err(1, "fclose(%s)", argv[1]);
 
 	/*
+	 * 1a. If there are no ports, there is no INDEX.
+	 */
+	if (pplen == 0)
+		return 0;
+
+	/*
 	 * 2. Sort the ports according to port directory.
 	 */
 	for (i = pplen; i > 0; i--)