pop3.c: Fixed failure detection during TLS upgrade

pop3_state_upgrade_tls() would attempt to incorrectly complete the
upgrade to pop3s and start the CAPA command if
Curl_ssl_connect_nonblocking() returned a failure code and if ssldone
was set to TRUE. This would only happen when a non-blocking API hadn't
been provided by the SSL implementation and curlssl_connect() was
called underneath.

1 files changed, 9 insertions, 6 deletions

diff --git a/lib/pop3.c b/lib/pop3.c
index eabcd3004..9a9e81b20 100644
--- a/lib/pop3.c
+++ b/lib/pop3.c
@@ -568,10 +568,8 @@ static CURLcode pop3_state_starttls_resp(struct connectdata *conn,
     else
       result = pop3_state_capa(conn);
   }
-  else {
-    state(conn, POP3_UPGRADETLS);
+  else
     result = pop3_state_upgrade_tls(conn);
-  }
 
   return result;
 }
@@ -583,9 +581,14 @@ static CURLcode pop3_state_upgrade_tls(struct connectdata *conn)
 
   result = Curl_ssl_connect_nonblocking(conn, FIRSTSOCKET, &pop3c->ssldone);
 
-  if(pop3c->ssldone) {
-    pop3_to_pop3s(conn);
-    result = pop3_state_capa(conn);
+  if(!result) {
+    if(pop3c->state != POP3_UPGRADETLS)
+      state(conn, POP3_UPGRADETLS);
+
+    if(pop3c->ssldone) {
+      pop3_to_pop3s(conn);
+      result = pop3_state_capa(conn);
+    }
   }
 
   return result;