accept connections from IPv6 link-local addresses

diff -NarU1 a/pyftpdlib/handlers.py b/pyftpdlib2/handlers.py
--- a/pyftpdlib/handlers.py	2024-06-23 14:03:38
+++ b/pyftpdlib/handlers.py	2025-08-22 21:59:40
@@ -451,3 +451,4 @@
 
-        local_ip = self.cmd_channel.socket.getsockname()[0]
+        sockname = list(self.cmd_channel.socket.getsockname())
+        local_ip = sockname[0]
         if local_ip in self.cmd_channel.masquerade_address_map:
@@ -459,3 +460,5 @@
 
-        if self.cmd_channel.server.socket.family != socket.AF_INET:
+        if local_ip.startswith('fe') and local_ip[2:3] in "89ab":
+            af = socket.AF_INET6  # link-local
+        elif self.cmd_channel.server.socket.family != socket.AF_INET:
             # dual stack IPv4/IPv6 support
@@ -472,3 +475,4 @@
             # free unprivileged random port.
-            self.bind((local_ip, 0))
+            sockname[1] = 0
+            self.bind(tuple(sockname))
         else:
@@ -478,4 +482,5 @@
                 self.set_reuse_addr()
+                sockname[1] = port
                 try:
-                    self.bind((local_ip, port))
+                    self.bind(tuple(sockname))
                 except PermissionError:
@@ -495,3 +500,4 @@
                         else:
-                            self.bind((local_ip, 0))
+                            sockname[1] = 0
+                            self.bind(tuple(sockname))
                             self.cmd_channel.log(