more tests with reply source != target

The tests for --check-source verify that Echo reply packets
from a source IP that was not used as the target of the Echo
request are not accepted.  It does so for default fping, for
use with -c, and for use with -C.  Test if the source address
is really printed without --check-source, but with -c or -C.

ci/test-05-options-c-e.pl

@@ -1,6 +1,6 @@
 #!/usr/bin/perl -w
 
-use Test::Command tests => 63;
+use Test::Command tests => 69;
 use Test::More;
 
 #  -c n           count of pings to send to each target (default 1)
@@ -64,6 +64,18 @@
 });
 }
 
+# fping -c n ff02::1
+SKIP: {
+    if($ENV{SKIP_IPV6}) {
+        skip 'Skip IPv6 tests', 3;
+    }
+    my $cmd = Test::Command->new(cmd => "fping -c 1 ff02::1");
+    $cmd->exit_is_num(0);
+    $cmd->stdout_like(qr{ff02::1 : \[0\], 64 bytes, \d\.\d+ ms \(\d\.\d+ avg, 0% loss\)\n});
+    $cmd->stderr_like(qr{ \[<- .*\]
+ff02::1 : xmt/rcv/%loss = 1/1/0%, min/avg/max = \d\.\d+/\d\.\d+/\d\.\d+\n});
+}
+
 # fping -C n
 {
 my $cmd = Test::Command->new(cmd => "fping -4 -C 2 -p 100 localhost 127.0.0.1");
@@ -128,6 +140,17 @@
 });
 }
 
+# fping -C n ff02::1
+SKIP: {
+    if($ENV{SKIP_IPV6}) {
+        skip 'Skip IPv6 tests', 3;
+    }
+    my $cmd = Test::Command->new(cmd => "fping -C 1 ff02::1");
+    $cmd->exit_is_num(0);
+    $cmd->stdout_like(qr{ff02::1 : \[0\], 64 bytes, \d\.\d+ ms \(\d\.\d+ avg, 0% loss\)\n});
+    $cmd->stderr_like(qr{ \[<- .*\]\nff02::1 : \d\.\d+\n});
+}
+
 # fping --check-source
 {
 my $cmd = Test::Command->new(cmd => "fping --check-source 127.0.0.1 127.0.0.2");