[PATCH v9] tun: Avoid sign-compare warning in header_modify_read_write_return

From: Frank Lichtenheld <[email protected]>

Since we already check that the value is positive
just make the implicit cast explicit.

Change-Id: I2ca40d0d86599896b38ea1467313b6a6cdc8339c
Signed-off-by: Frank Lichtenheld <[email protected]>
Acked-by: Razvan Cojocaru <[email protected]>
Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/1527
---

This change was reviewed on Gerrit and approved by at least one
developer. I request to merge it to master.

Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/1527
This mail reflects revision 9 of this Change.

Acked-by according to Gerrit (reflected above):
Razvan Cojocaru <[email protected]>

        
diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
index f46802f..28ec7b8 100644
--- a/src/openvpn/tun.c
+++ b/src/openvpn/tun.c
@@ -1706,17 +1706,12 @@
 #include <netinet/ip.h>
 #include <sys/uio.h>
 
-#if defined(__GNUC__) || defined(__clang__)
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wsign-compare"
-#endif
-
 static inline ssize_t
 header_modify_read_write_return(ssize_t len)
 {
     if (len > 0)
     {
-        return len > sizeof(u_int32_t) ? len - sizeof(u_int32_t) : 0;
+        return (size_t)len > sizeof(u_int32_t) ? len - sizeof(u_int32_t) : 0;
     }
     else
     {
@@ -1724,10 +1719,6 @@
     }
 }
 
-#if defined(__GNUC__) || defined(__clang__)
-#pragma GCC diagnostic pop
-#endif
-
 static ssize_t
 write_tun_header(struct tuntap *tt, uint8_t *buf, int len)
 {