s-s-d: Make sure that we get a meaningful errno on parse_unsigned()

Initialize errno to 0 before returning on any error condition, not just
before strtol(3), so that when we call fatal() we get a meaningful value
in errno.

2 files changed, 3 insertions, 1 deletions

diff --git a/debian/changelog b/debian/changelog
index 6d95110ae..e2f7bd67d 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,6 +1,8 @@
 dpkg (1.19.5) UNRELEASED; urgency=medium
 
   [ Guillem Jover ]
+  * start-stop-daemon: Make sure that we get a meaningful errno on
+    parse_unsigned(), so that the error messages always make sense.
   * Build system:
     - Check whether this dist is a release, based only on the version format.
       This will avoid having to do a two staged release to get a proper perl
diff --git a/utils/start-stop-daemon.c b/utils/start-stop-daemon.c
index 7a52643f8..035ee0306 100644
--- a/utils/start-stop-daemon.c
+++ b/utils/start-stop-daemon.c
@@ -448,10 +448,10 @@ parse_unsigned(const char *string, int base, int *value_r)
 	long value;
 	char *endptr;
 
+	errno = 0;
 	if (!string[0])
 		return -1;
 
-	errno = 0;
 	value = strtol(string, &endptr, base);
 	if (string == endptr || *endptr != '\0' || errno != 0)
 		return -1;