updated for version 7.4.427
Problem: When an InsertCharPre autocommand executes system() typeahead may
be echoed and messes up the display. (Jacob Niehus)
Solution: Do not set cooked mode when invoked from ":silent".
diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 9aa97b7..688fc38 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -6093,6 +6093,12 @@
list items converted to NULs).
Pipes are not used.
+ When prepended by |:silent| the shell will not be set to
+ cooked mode. This is meant to be used for commands that do
+ not need the user to type. It avoids stray characters showing
+ up on the screen which require |CTRL-L| to remove. >
+ :silent let f = system('ls *.vim')
+<
Note: Use |shellescape()| or |::S| with |expand()| or
|fnamemodify()| to escape special characters in a command
argument. Newlines in {expr} may cause the command to fail.