Bug #22059. ftp_chdir() causes segfault. efree(ftp->pwd) was being called without knowing for certain that ftp->pwd

actually pointed anywhere.

Author: sgolemon

NEWS

@@ -3,6 +3,7 @@ PHP 4                                                                      NEWS
 ? ? ??? 200?, Version 5.0.0
 - Moved extensions to PECL (http://pear.php.net/): (James, Tal)
   . ext/fribidi
+- Fixed bug #22059 (ftp_chdir causes segfault). (Sara)
 - Fixed bug #20442 (upgraded bundled expat to 1.95.5). (Ilia)
 - Fixed bug #20155 (xmlrpc compile problem with ZE2). (Derick, Jan Schneider)
 - Changed get_extension_funcs() to return list of the built-in Zend Engine 

ext/ftp/ftp.c

@@ -473,7 +473,8 @@ ftp_chdir(ftpbuf_t *ftp, const char *dir)
 		return 0;
 	}
 
-	efree(ftp->pwd);
+	if (ftp->pwd)
+		efree(ftp->pwd);
 
 	if (!ftp_putcmd(ftp, "CWD", dir)) {
 		return 0;
@@ -494,7 +495,8 @@ ftp_cdup(ftpbuf_t *ftp)
 		return 0;
 	}
 
-	efree(ftp->pwd);
+	if (ftp->pwd)
+		efree(ftp->pwd);
 
 	if (!ftp_putcmd(ftp, "CDUP", NULL)) {
 		return 0;