Fix #80880: SSL_read on shutdown, ftp/proc_open

When `SSL_read()` after `SSL_shutdown()` fails with `SSL_ERROR_SYSCALL`,
we should not warn about this, because it is likely caused by the peer
having closed the connection without having sent a close_notify
shutdown alert.

Signed-off-by: Christoph M. Becker <cmbecker69@gmx.de>

Closes GH-6803.

Author: cmb69

NEWS

@@ -14,6 +14,10 @@ PHP                                                                        NEWS
   . Fixed bug #80024 (Duplication of info about inherited socket after pool
     removing). (Jakub Zelenka)
 
+- FTP:
+  . Fixed bug #80880 (SSL_read on shutdown, ftp/proc_open). (cmb, Jakub
+    Zelenka)
+
 - LibXML:
   . Fixed bug #73533 (Invalid memory access in php_libxml_xmlCheckUTF8). (cmb)
 

ext/ftp/ftp.c

@@ -1931,6 +1931,12 @@ static void ftp_ssl_shutdown(ftpbuf_t *ftp, php_socket_t fd, SSL *ssl_handle) {
 					/* SSL wants a write. Really odd. Let's bail out. */
 					done = 1;
 					break;
+				case SSL_ERROR_SYSCALL:
+					/* most likely the peer closed the connection without
+					   sending a close_notify shutdown alert;
+					   bail out to avoid raising a spurious warning */
+					done = 1;
+					break;
 				default:
 					if ((sslerror = ERR_get_error())) {
 						ERR_error_string_n(sslerror, buf, sizeof(buf));