Remove the default Net::Cmd::timeout()

This accidentally overrode the timeout() in Net::FTP's $IOCLASS. Instead,
we now document that timeout() needs to be provided by the Net::Cmd
sub-class (normally by inheriting from IO::Socket::INET or similar (which
in turn inherit from IO::Socket, which provides timeout()), which most
users seem to do anyway).

Similarly, document that close() most also be provided (normally by
inheriting from IO::Handle, which IO::Socket::INET or similar also do, via
IO::Socket).

This fixes CPAN RT#116345. Thanks to ppisar@redhat.com for the analysis.

3 files changed, 22 insertions, 11 deletions

diff --git a/Changes b/Changes
index 1d574b7..d7d4cd8 100644
--- a/Changes
+++ b/Changes
@@ -2,7 +2,19 @@ Revision history for Perl distribution libnet
 
 3.10 Development
 
-    - TODO
+    - Removed the default Net::Cmd::timeout() since it inadvertently overrode
+      the timeout() method in whatever IO::Socket::INET-like class sub-classes
+      of Net::Cmd also derive from (at least in cases where Net::Cmd takes
+      precedence in the method resolution, which it should do so that
+      Net::Cmd::getline() overrides IO::Handle::getline()).
+
+      This does cause problems for any Net::Cmd sub-classes that don't provide
+      (by whatever means) the necessary parts of the interface of
+      IO::Socket::INET, but since they mostly seem to anyway (apart from the one
+      that led to the CPAN RT#110978 report!) this is now simply a documented
+      requirement.
+
+      [CPAN RT#116345]
 
 3.09 2016-07-19
 
diff --git a/lib/Net/Cmd.pm b/lib/Net/Cmd.pm
index e739c89..38054c4 100644
--- a/lib/Net/Cmd.pm
+++ b/lib/Net/Cmd.pm
@@ -190,8 +190,6 @@ sub set_status {
   1;
 }
 
-sub timeout { 0 }
-
 sub _syswrite_with_timeout {
   my $cmd = shift;
   my $line = shift;
@@ -656,10 +654,15 @@ Net::Cmd - Network Command class (as used by FTP, SMTP etc)
 
 =head1 DESCRIPTION
 
-C<Net::Cmd> is a collection of methods that can be inherited by a sub class
-of C<IO::Handle>. These methods implement the functionality required for a
+C<Net::Cmd> is a collection of methods that can be inherited by a sub-class
+of C<IO::Socket::INET>. These methods implement the functionality required for a
 command based protocol, for example FTP and SMTP.
 
+If your sub-class does not also derive from C<IO::Socket::INET> or similar (e.g.
+C<IO::Socket::IP>, C<IO::Socket::INET6> or C<IO::Socket::SSL>) then you must
+provide the following methods by other means yourself: C<close()> and
+C<timeout()>.
+
 =head1 USER METHODS
 
 These methods provide a user interface to the C<Net::Cmd> object.
@@ -750,12 +753,6 @@ command server.
 
 Returns undef upon failure.
 
-=item timeout ()
-
-Returns the timeout value for this class, in seconds. The timeout provided
-by the default implementation is 0; subclasses may override this if they
-choose.
-
 =item unsupported ()
 
 Sets the status code to 580 and the response text to 'Unsupported command'.
diff --git a/t/datasend.t b/t/datasend.t
index 05903fb..0aea9d4 100644
--- a/t/datasend.t
+++ b/t/datasend.t
@@ -21,6 +21,8 @@ BEGIN {
   use Net::Cmd;
   our @ISA = qw(Net::Cmd IO::File);
 
+  sub timeout { 0 }
+
   sub new {
     my $fh = shift->new_tmpfile;
     binmode($fh);