rename ftp_ssl: the struct field is used for many protocols

Now called 'use_ssl' instead, which better matches the current CURLOPT
name and since the option is used for all pingpong protocols (at least)
it makes sense to not use 'ftp' in the name.

lib/ftp.c

@@ -2493,7 +2493,7 @@ static CURLcode ftp_statemach_act(struct connectdata *conn)
       }
 #endif
 
-      if(data->set.ftp_ssl && !conn->ssl[FIRSTSOCKET].use) {
+      if(data->set.use_ssl && !conn->ssl[FIRSTSOCKET].use) {
         /* We don't have a SSL/TLS connection yet, but FTPS is
            requested. Try a FTPS connection now */
 
@@ -2549,7 +2549,7 @@ static CURLcode ftp_statemach_act(struct connectdata *conn)
         /* remain in this same state */
       }
       else {
-        if(data->set.ftp_ssl > CURLUSESSL_TRY)
+        if(data->set.use_ssl > CURLUSESSL_TRY)
           /* we failed and CURLUSESSL_CONTROL or CURLUSESSL_ALL is set */
           result = CURLE_USE_SSL_FAILED;
         else
@@ -2572,7 +2572,7 @@ static CURLcode ftp_statemach_act(struct connectdata *conn)
 
     case FTP_PBSZ:
       PPSENDF(&ftpc->pp, "PROT %c",
-              data->set.ftp_ssl == CURLUSESSL_CONTROL ? 'C' : 'P');
+              data->set.use_ssl == CURLUSESSL_CONTROL ? 'C' : 'P');
       state(conn, FTP_PROT);
 
       break;
@@ -2581,10 +2581,10 @@ static CURLcode ftp_statemach_act(struct connectdata *conn)
       if(ftpcode/100 == 2)
         /* We have enabled SSL for the data connection! */
         conn->ssl[SECONDARYSOCKET].use =
-          (data->set.ftp_ssl != CURLUSESSL_CONTROL) ? TRUE : FALSE;
+          (data->set.use_ssl != CURLUSESSL_CONTROL) ? TRUE : FALSE;
       /* FTP servers typically responds with 500 if they decide to reject
          our 'P' request */
-      else if(data->set.ftp_ssl > CURLUSESSL_CONTROL)
+      else if(data->set.use_ssl > CURLUSESSL_CONTROL)
         /* we failed and bails out */
         return CURLE_USE_SSL_FAILED;
 

lib/imap.c

@@ -580,7 +580,7 @@ static CURLcode imap_statemach_act(struct connectdata *conn)
       return CURLE_FTP_WEIRD_SERVER_REPLY;
     }
 
-    if(data->set.ftp_ssl && !conn->ssl[FIRSTSOCKET].use) {
+    if(data->set.use_ssl && !conn->ssl[FIRSTSOCKET].use) {
       /* We don't have a SSL/TLS connection yet, but SSL is requested. Switch
          to TLS connection now */
       const char *str;

lib/pop3.c

@@ -521,7 +521,7 @@ static CURLcode pop3_statemach_act(struct connectdata *conn)
         return CURLE_FTP_WEIRD_SERVER_REPLY;
       }
 
-      if(data->set.ftp_ssl && !conn->ssl[FIRSTSOCKET].use) {
+      if(data->set.use_ssl && !conn->ssl[FIRSTSOCKET].use) {
         /* We don't have a SSL/TLS connection yet, but SSL is requested. Switch
            to TLS connection now */
         result = Curl_pp_sendf(&pop3c->pp, "STLS");

lib/smtp.c

@@ -507,7 +507,7 @@ static CURLcode smtp_state_starttls_resp(struct connectdata *conn,
   (void)instate; /* no use for this yet */
 
   if(smtpcode != 220) {
-    if(data->set.ftp_ssl != CURLUSESSL_TRY) {
+    if(data->set.use_ssl != CURLUSESSL_TRY) {
       failf(data, "STARTTLS denied. %c", smtpcode);
       result = CURLE_LOGIN_DENIED;
     }
@@ -557,7 +557,7 @@ static CURLcode smtp_state_ehlo_resp(struct connectdata *conn,
   (void)instate; /* no use for this yet */
 
   if(smtpcode/100 != 2) {
-    if((data->set.ftp_ssl <= CURLUSESSL_TRY || conn->ssl[FIRSTSOCKET].use) &&
+    if((data->set.use_ssl <= CURLUSESSL_TRY || conn->ssl[FIRSTSOCKET].use) &&
      !conn->bits.user_passwd)
       result = smtp_state_helo(conn);
     else {
@@ -565,7 +565,7 @@ static CURLcode smtp_state_ehlo_resp(struct connectdata *conn,
       result = CURLE_LOGIN_DENIED;
     }
   }
-  else if(data->set.ftp_ssl && !conn->ssl[FIRSTSOCKET].use) {
+  else if(data->set.use_ssl && !conn->ssl[FIRSTSOCKET].use) {
     /* We don't have a SSL/TLS connection yet, but SSL is requested. Switch
        to TLS connection now */
     result = Curl_pp_sendf(&conn->proto.smtpc.pp, "STARTTLS");

lib/url.c

@@ -2169,7 +2169,7 @@ CURLcode Curl_setopt(struct SessionHandle *data, CURLoption option,
     /*
      * Make transfers attempt to use SSL/TLS.
      */
-    data->set.ftp_ssl = (curl_usessl)va_arg(param, long);
+    data->set.use_ssl = (curl_usessl)va_arg(param, long);
     break;
 #endif
   case CURLOPT_FTPSSLAUTH:

lib/urldata.h

@@ -1493,7 +1493,7 @@ struct UserDefined {
   bool ftp_use_eprt;     /* if EPRT is to be attempted or not */
   bool ftp_use_pret;     /* if PRET is to be used before PASV or not */
 
-  curl_usessl ftp_ssl;   /* if AUTH TLS is to be attempted etc, for FTP or
+  curl_usessl use_ssl;   /* if AUTH TLS is to be attempted etc, for FTP or
                             IMAP or POP3 or others! */
   curl_ftpauth ftpsslauth; /* what AUTH XXX to be attempted */
   curl_ftpccc ftp_ccc;   /* FTP CCC options */