Added check for pyftpdlib when running FTP test.

tests/__init__.py

@@ -131,12 +131,23 @@ def has_proxy ():
         s.close()
         return True
     except StandardError:
-        pass
-    return False
+        return False
 
 need_proxy = _need_func(has_proxy, "proxy")
 
 
+@memoized
+def has_pyftpdlib ():
+    """Test if pyftpdlib is available."""
+    try:
+        import pyftpdlib
+        return True
+    except ImportError:
+        return False
+
+need_pyftpdlib = _need_func(has_pyftpdlib, "pyftpdlib")
+
+
 @memoized
 def has_newsserver (server):
     try:

tests/checker/ftpserver.py

@@ -20,7 +20,6 @@ Define http test support classes for LinkChecker tests.
 import sys
 import os
 import time
-from pyftpdlib import ftpserver
 from . import LinkCheckTest
 
 
@@ -62,6 +61,7 @@ def start_server (host, port):
         if "kill" in msg:
             sys.exit(0)
 
+    from pyftpdlib import ftpserver
     authorizer = ftpserver.DummyAuthorizer()
     datadir = os.path.join(os.path.dirname(__file__), 'data')
     authorizer.add_anonymous(datadir)

tests/checker/test_ftp.py

@@ -17,12 +17,14 @@
 """
 FTP checking.
 """
+from .. import need_pyftpdlib
 from .ftpserver import FtpServerTest
 
 
 class TestFtp (FtpServerTest):
     """Test ftp: link checking."""
 
+    @need_pyftpdlib
     def test_ftp (self):
         try:
             # ftp two slashes