From 776cf7461fa54445a40df17c40cfd024b6f09578 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 7 Nov 2018 19:14:47 +0100
Subject: [PATCH] random-util: if zero random bytes are requested we can always
 fulfill the request

---
 src/basic/random-util.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/basic/random-util.c b/src/basic/random-util.c
index 1c54b07fbbc..922b5a57b0f 100644
--- a/src/basic/random-util.c
+++ b/src/basic/random-util.c
@@ -76,6 +76,9 @@ int genuine_random_bytes(void *p, size_t n, RandomFlags flags) {
          * the random pool is fully initialized or not.  Otherwise, it will return success if at least some random
          * bytes were successfully acquired, and an error if the kernel has no entropy whatsover for us. */
 
+        if (n == 0)
+                return 0;
+
         /* Use the getrandom() syscall unless we know we don't have it. */
         if (have_syscall != 0 && !HAS_FEATURE_MEMORY_SANITIZER) {
 
-- 
2.47.3