updated for version 7.3.742
Problem:    Leaking memory when :vimgrep restores the directory.
Solution:   Free the allocated memory. (Christian Brabandt)
diff --git a/src/quickfix.c b/src/quickfix.c
index 7dbdb96..2a485f0 100644
--- a/src/quickfix.c
+++ b/src/quickfix.c
@@ -3515,6 +3515,7 @@
 	    ea.cmdidx = (curwin->w_localdir == NULL) ? CMD_cd : CMD_lcd;
 	    ex_cd(&ea);
 	}
+	vim_free(dirname_now);
     }
 }