Improve documentation of osl_get_nth_row().

Make it explicit that it is invalid to pass zero.

diff --git a/osl.h.m4 b/osl.h.m4
index 007450839e4620c59415b54db6dc4920489f6f98..956be2a0caea626b342092a72d909faf292afde9 100644 (file)
--- a/osl.h.m4
+++ b/osl.h.m4
@@ -561,8 +561,8 @@ DECLARE_FUNCTION(
        «Retrieve the n-th order statistic with respect to the compare
        function of the rbtree column col_num. In other words, get the row
        with n-th greatest value in column col_num. It is an error if col_num
-       is not a rbtree column, or if n is larger than the number of rows in
-       the table.»,
+       is not a rbtree column or if n is out of range, i.e., zero or larger
+       than the number of rows in the table.»,
 
        «int»,
        «Standard»