fix ping TTL option for OSX (dotnet/corefx#35506)

Commit migrated from https://github.com/dotnet/corefx/commit/ecad65740b41b1502188ac6b412ade53fb54ba3e

diff --git a/src/libraries/Common/src/System/Net/NetworkInformation/UnixCommandLinePing.cs b/src/libraries/Common/src/System/Net/NetworkInformation/UnixCommandLinePing.cs
index 73e9d9c..3a5c413 100644 (file)
--- a/src/libraries/Common/src/System/Net/NetworkInformation/UnixCommandLinePing.cs
+++ b/src/libraries/Common/src/System/Net/NetworkInformation/UnixCommandLinePing.cs
@@ -84,10 +84,17 @@ namespace System.Net.NetworkInformation
 
             if (ttl > 0)
             {
-                if (!ipv4 && s_isBSD)
+                if (s_isBSD)
                 {
-                    // OSX and FreeBSD use -h to set hop limit for IPv6
-                    sb.Append(" -h ");
+                    // OSX and FreeBSD use -h to set hop limit for IPv6 and -m ttl for IPv4
+                    if (ipv4)
+                    {
+                        sb.Append(" -m ");
+                    }
+                    else
+                    {
+                        sb.Append(" -h ");
+                    }
                 }
                 else
                 {