The code expects id_t and mode_t to be unsigned, so the code now defines

each one to be unsigned int (instead of int) when the type is missing.

rsync.h

@@ -409,13 +409,13 @@ enum msgcode {
 #include "lib/pool_alloc.h"
 
 #ifndef HAVE_ID_T
-typedef int id_t;
+typedef unsigned int id_t;
 #endif
 #ifndef HAVE_PID_T
 typedef int pid_t;
 #endif
 #ifndef HAVE_MODE_T
-typedef int mode_t;
+typedef unsigned int mode_t;
 #endif
 #ifndef HAVE_OFF_T
 typedef long off_t;