Never call qsort on potentially NULL arrays

This extends 62678ded 'efi: never call qsort on potentially
NULL arrays' to all other places where qsort is used and it
is not obvious that the count is non-zero.

1 files changed, 12 insertions, 0 deletions

diff --git a/src/shared/util.h b/src/shared/util.h
index 26af5b30a..09e556d01 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -772,3 +772,15 @@ bool id128_is_valid(const char *s) _pure_;
 void parse_user_at_host(char *arg, char **user, char **host);
 
 int split_pair(const char *s, const char *sep, char **l, char **r);
+
+/**
+ * Normal qsort requires base to be nonnull. Here were require
+ * that only if nmemb > 0.
+ */
+static inline void qsort_safe(void *base, size_t nmemb, size_t size,
+                              int (*compar)(const void *, const void *)) {
+        if (nmemb) {
+                assert(base);
+                qsort(base, nmemb, size, compar);
+        }
+}