sizeof(old_cwd) evaluated to sizeof(char *) after last commit, so old_cwd

was not set correctly.

main/main.c

@@ -1132,8 +1132,8 @@ PHPAPI void php_execute_script(zend_file_handle *primary_file CLS_DC ELS_DC PLS_
 			return;
 		}
 	}
-
-	old_cwd = do_alloca(4096);
+#define OLD_CWD_SIZE 4096
+	old_cwd = do_alloca(OLD_CWD_SIZE);
 	old_cwd[0] = '\0';
 
 	if (setjmp(EG(bailout))!=0) {
@@ -1149,7 +1149,7 @@ PHPAPI void php_execute_script(zend_file_handle *primary_file CLS_DC ELS_DC PLS_
 
 	if (primary_file->type == ZEND_HANDLE_FILENAME 
 			&& primary_file->filename) {
-		V_GETCWD(old_cwd, sizeof(old_cwd)-1);
+		V_GETCWD(old_cwd, OLD_CWD_SIZE-1);
 		V_CHDIR_FILE(primary_file->filename);
 	}