commit 1f6f39b84f81cfa6bc243557a68eebeeac7e8ea3
Author: Robert Schiele <rschiele@gmail.com>
Date:   Mon Mar 14 09:18:08 2016 +0100

    reorder -I option parsing
    
    This changes -I option parsing in a way that device is only assigned
    if neither an IPv4 nor an IPv6 address is detected.  Otherwise those
    addresses are misinterpreted as device names and as such will cause
    error messages later in the code.
    
    Signed-off-by: Robert Schiele <rschiele@gmail.com>

diff --git a/ping.c b/ping.c
index c42d6eb..498c0e8 100644
--- a/ping.c
+++ b/ping.c
@@ -279,10 +279,6 @@ main(int argc, char **argv)
 			break;
 		}
 		case 'I':
-			if (inet_pton(AF_INET, optarg, &source.sin_addr) > 0)
-				options |= F_STRICTSOURCE;
-			else
-				device = optarg;
 			/* IPv6 */
 			if (strchr(optarg, ':')) {
 				char *p, *addr = strdup(optarg);
@@ -306,6 +302,8 @@ main(int argc, char **argv)
 				options |= F_STRICTSOURCE;
 
 				free(addr);
+			} else if (inet_pton(AF_INET, optarg, &source.sin_addr) > 0) {
+				options |= F_STRICTSOURCE;
 			} else {
 				device = optarg;
 			}