patch 8.2.4740: when expand() fails there is no error message
Problem: When expand() fails there is no error message.
Solution: When 'verbose' is set give an error message.
diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index 4fb12ff..f6a791d 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -2270,6 +2270,9 @@
is not defined, an empty string is used. Using "%:p" in a
buffer with no name, results in the current directory, with a
'/' added.
+ When 'verbose' is set then expanding '%', '#' and <> items
+ will result in an error message if the argument cannot be
+ expanded.
When {string} does not start with '%', '#' or '<', it is
expanded like a file name is expanded on the command line.