Fix writepid for retvalue 0.

daemon/unbound.c

@@ -365,6 +365,11 @@ writepid (const char* pidfile, pid_t pid)
 				pidfile, strerror(errno));
 			close(fd);
 			return 0;
+		} else if(r == 0) {
+			log_err("cannot write any bytes to pidfile %s: "
+				"write returns 0 bytes written", pidfile);
+			close(fd);
+			return 0;
 		}
 		count += r;
 	}

doc/Changelog

@@ -8,6 +8,7 @@
 	- Option to toggle udp-connect, default is enabled.
 	- Fix for #303 CVE-2020-28935 : Fix that symlink does not interfere
 	  with chown of pidfile.
+	- Further fix for it and retvalue 0 fix for it.
 
 12 November 2020: Wouter
 	- Fix to connect() to UDP destinations, default turned on,