[mod_cgi] issue trace and exit if execve() fails (closes #2302)

(replace SEGFAULT if execve() fails)

From: Glenn Strauss <gstrauss@gluelogic.com>

git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@3079 152afb58-edef-0310-8abb-c4023f1b3aa9

NEWS

@@ -11,6 +11,7 @@ NEWS
   * [mod_cgi] use MAP_PRIVATE to mmap temporary file (fixes #2715)
   * [core] do not send SIGHUP to process group unless server.max-workers is used (fixes #2711)
   * [mod_cgi] edge case chdir "/" when docroot "/" (fixes #2460)
+  * [mod_cgi] issue trace and exit if execve() fails (closes #2302)
 
 - 1.4.39 - 2016-01-02
   * [core] fix memset_s call (fixes #2698)

src/mod_cgi.c

@@ -1095,11 +1095,10 @@ static int cgi_create_env(server *srv, connection *con, plugin_data *p, buffer *
 		/* exec the cgi */
 		execve(args[0], args, env.ptr);
 
-		/* log_error_write(srv, __FILE__, __LINE__, "sss", "CGI failed:", strerror(errno), args[0]); */
-
-		/* */
-		SEGFAULT();
-		break;
+		/* most log files may have been closed/redirected by this point,
+		 * though stderr might still point to lighttpd.breakage.log */
+		perror(args[0]);
+		_exit(1);
 	}
 	case -1:
 		/* error */