From e38bebb9ee805df6848f42845e71c8da8a821ad3 Mon Sep 17 00:00:00 2001 From: Dan Hemberger <846186+hemberger@users.noreply.github.com> Date: Sat, 22 Apr 2023 21:41:23 -0700 Subject: gh-81403: Fix for CacheFTPHandler in urllib (#13951) bpo-37222: Fix for CacheFTPHandler in urllib A call to FTP.ntransfercmd must be followed by FTP.voidresp to clear the "end transfer" message. Without this, the client and server get out of sync, which will result in an error if the FTP instance is reused to open a second URL. This scenario occurs for even the most basic usage of CacheFTPHandler. Reverts the patch merged as a resolution to bpo-16270 and adds a test case for the CacheFTPHandler in test_urllib2net.py. Co-authored-by: Senthil Kumaran --- Lib/test/test_urllib2net.py | 2 ++ Lib/urllib/request.py | 6 ++++++ 2 files changed, 8 insertions(+) diff --git a/Lib/test/test_urllib2net.py b/Lib/test/test_urllib2net.py index 5da41c3..d8d882b 100644 --- a/Lib/test/test_urllib2net.py +++ b/Lib/test/test_urllib2net.py @@ -134,8 +134,10 @@ class OtherNetworkTests(unittest.TestCase): # They do sometimes catch some major disasters, though. def test_ftp(self): + # Testing the same URL twice exercises the caching in CacheFTPHandler urls = [ 'ftp://www.pythontest.net/README', + 'ftp://www.pythontest.net/README', ('ftp://www.pythontest.net/non-existent-file', None, urllib.error.URLError), ] diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py index 19e2e5b..5314b3f 100644 --- a/Lib/urllib/request.py +++ b/Lib/urllib/request.py @@ -2475,7 +2475,13 @@ class ftpwrapper: return (ftpobj, retrlen) def endtransfer(self): + if not self.busy: + return self.busy = 0 + try: + self.ftp.voidresp() + except ftperrors(): + pass def close(self): self.keepalive = False -- cgit v0.12