Incorrect dir remembered on second MKD failure with CURLFTP_CREATE_DIR_RETRY

[youngr225]

I did this

Simultaneous file transfer to same directory using curl_multi and CURLFTP_CREATE_DIR_RETRY.

I expected the following

Second MKD failure stores last successful CWD path in ftpc->prevpath.

> CWD 1
< 250 Directory successfully changed.
> CWD 2
< 550 Failed to change directory.
> MKD 2
< 550 Create directory operation failed.
> CWD 2
< 250 Directory successfully changed.
> CWD 3
< 550 Failed to change directory.
> MKD 3
< 550 Create directory operation failed.
* Failed to MKD dir: 550
* Remembering we are in dir "/ftp_root/1/2/3/"            # should not contain final 3 dir
* Uploaded unaligned file size (0 out of 351272 bytes)
* Connection #5 to host xxxx left intact

curl/libcurl version

7.72.0

operating system

openSUSE 15.2
Linux linux-jxih 5.3.18-lp152.95-default #1 SMP Tue Oct 5 07:30:50 UTC 2021 (7cfc6af) x86_64 x86_64 x86_64 GNU/Linux

proposed patch

Change behavior to allow one MKD failure per directory.

diff --git a/lib/ftp.c b/lib/ftp.c
index 0b9c9b73..db713fdd 100644
--- a/lib/ftp.c
+++ b/lib/ftp.c
@@ -876,9 +876,9 @@ static CURLcode ftp_state_cwd(struct Curl_easy *data,
 
     ftpc->count2 = 0; /* count2 counts failed CWDs */
 
-    /* count3 is set to allow a MKD to fail once. In the case when first CWD
-       fails and then MKD fails (due to another session raced it to create the
-       dir) this then allows for a second try to CWD to it */
+    /* count3 is set to allow a MKD to fail once per dir. In the case when the
+       first CWD fails and then MKD fails (due to another session raced it to
+       create the dir) this then allows for a second try to CWD to it */
     ftpc->count3 = (data->set.ftp_create_missing_dirs == 2)?1:0;
 
     if(conn->bits.reuse && ftpc->entrypath &&
@@ -3018,6 +3018,7 @@ static CURLcode ftp_statemachine(struct Curl_easy *data,
       else {
         /* success */
         ftpc->count2 = 0;
+        ftpc->count3 = (data->set.ftp_create_missing_dirs == 2) ? 1 : 0;
         if(++ftpc->cwdcount <= ftpc->dirdepth)
           /* send next CWD */
           result = Curl_pp_sendf(data, &ftpc->pp, "CWD %s",

[bagder]

I think this would be much clearer if you would move the ftpc->count3 assignment to be just before MKD is sent (line ~3005), and only do it there.

Also, any chance you can make a "real" pull request out of this, or would you like me to do it for you?