FTP: when EPSV gets a 229 but fails to connect, retry with PASV

This is a regression as this logic used to work. It isn't clear when it
broke, but I'm assuming in 7.28.0 when we went all-multi internally.

This likely never worked with the multi interface. As the failed
connection is detected once the multi state has reached DO_MORE, the
Curl_do_more() function was now expanded somewhat so that the
ftp_do_more() function can request to go "back" to the previous state
when it makes another attempt - using PASV.

Added test case 1233 to verify this fix. It has the little issue that it
assumes no service is listening/accepting connections on port 1...

Reported-by: byte_bucket in the #curl IRC channel

1 files changed, 46 insertions, 0 deletions

diff --git a/tests/data/test1233 b/tests/data/test1233
new file mode 100644
index 000000000..caf0527f2
--- /dev/null
+++ b/tests/data/test1233
@@ -0,0 +1,46 @@
+<testcase>
+<info>
+<keywords>
+FTP
+</keywords>
+</info>
+
+# Server-side
+<reply>
+<servercmd>
+# Assuming there's nothing listening on port 1
+REPLY EPSV 229 Entering Passiv Mode (|||1|)
+</servercmd>
+<data>
+here are some bytes
+</data>
+</reply>
+
+# Client-side
+<client>
+<server>
+ftp
+</server>
+ <name>
+FTP failing to connect to EPSV port, switching to PASV
+ </name>
+ <command>
+ftp://%HOSTIP:%FTPPORT/1233
+</command>
+</client>
+
+# Verify data after the test has been "shot"
+<verify>
+<protocol>
+USER anonymous

+PASS ftp@example.com

+PWD

+EPSV

+PASV

+TYPE I

+SIZE 1233

+RETR 1233

+QUIT

+</protocol>
+</verify>
+</testcase>