patch 7.4.1494
Problem:    clr_history() does not work properly.
Solution:   Increment hisptr. Add a test. (Yegappan Lakshmanan)
diff --git a/src/ex_getln.c b/src/ex_getln.c
index 96c3a8c..f9791f5 100644
--- a/src/ex_getln.c
+++ b/src/ex_getln.c
@@ -5783,6 +5783,7 @@
 	{
 	    vim_free(hisptr->hisstr);
 	    clear_hist_entry(hisptr);
+	    hisptr++;
 	}
 	hisidx[histype] = -1;	/* mark history as cleared */
 	hisnum[histype] = 0;	/* reset identifier counter */