updated for version 7.3.1293
Problem:    Put in empty buffer cannot be undone.
Solution:   Save one more line for undo. (Ozaki)
diff --git a/src/ops.c b/src/ops.c
index eaad703..ab3d636 100644
--- a/src/ops.c
+++ b/src/ops.c
@@ -3499,7 +3499,7 @@
 	    ++lnum;
 	/* In an empty buffer the empty line is going to be replaced, include
 	 * it in the saved lines. */
-	if ((bufempty() ? u_save(0, 1) : u_save(lnum - 1, lnum)) == FAIL)
+	if ((bufempty() ? u_save(0, 2) : u_save(lnum - 1, lnum)) == FAIL)
 	    goto end;
 #ifdef FEAT_FOLDING
 	if (dir == FORWARD)