- Issue #16038: CVE-2013-1752: ftplib: Limit amount of data read by
  limiting the call to readline().  Original patch by Michał
  Jastrzębski and Giampaolo Rodola.

with test fixes by Serhiy Storchaka.
diff --git a/Lib/ftplib.py b/Lib/ftplib.py
index 22decb2..a3c6475 100644
--- a/Lib/ftplib.py
+++ b/Lib/ftplib.py
@@ -54,6 +54,8 @@
 
 # The standard FTP server control port
 FTP_PORT = 21
+# The sizehint parameter passed to readline() calls
+MAXLINE = 8192
 
 
 # Exception raised when an error or invalid response is received
@@ -100,6 +102,7 @@
     debugging = 0
     host = ''
     port = FTP_PORT
+    maxline = MAXLINE
     sock = None
     file = None
     welcome = None
@@ -179,7 +182,9 @@
     # Internal: return one line from the server, stripping CRLF.
     # Raise EOFError if the connection is closed
     def getline(self):
-        line = self.file.readline()
+        line = self.file.readline(self.maxline + 1)
+        if len(line) > self.maxline:
+            raise Error("got more than %d bytes" % self.maxline)
         if self.debugging > 1:
             print '*get*', self.sanitize(line)
         if not line: raise EOFError
@@ -421,7 +426,9 @@
         conn = self.transfercmd(cmd)
         fp = conn.makefile('rb')
         while 1:
-            line = fp.readline()
+            line = fp.readline(self.maxline + 1)
+            if len(line) > self.maxline:
+                raise Error("got more than %d bytes" % self.maxline)
             if self.debugging > 2: print '*retr*', repr(line)
             if not line:
                 break
@@ -473,7 +480,9 @@
         self.voidcmd('TYPE A')
         conn = self.transfercmd(cmd)
         while 1:
-            buf = fp.readline()
+            buf = fp.readline(self.maxline + 1)
+            if len(buf) > self.maxline:
+                raise Error("got more than %d bytes" % self.maxline)
             if not buf: break
             if buf[-2:] != CRLF:
                 if buf[-1] in CRLF: buf = buf[:-1]