runtime(doc): Clarify the behaviour of command completion functions

closes: #19294

Signed-off-by: Christian Brabandt <cb@256bit.org>

diff --git a/runtime/doc/map.txt b/runtime/doc/map.txt
index ee46180a658498f41db1c89625fb1c2064666f6e..7ff9cfc0762c459a735b001cae4c15eb213ada24 100644 (file)
--- a/runtime/doc/map.txt
+++ b/runtime/doc/map.txt
@@ -1,4 +1,4 @@
-*map.txt*      For Vim version 9.1.  Last change: 2025 Nov 09
+*map.txt*      For Vim version 9.1.  Last change: 2026 Feb 02
 
 
                  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -1695,7 +1695,8 @@ candidates as a Vim List.  Non-string items in the list are ignored.
 
 The function arguments are:
        ArgLead         the leading portion of the argument currently being
-                       completed on
+                       completed on; note that this only captures the current
+                       space-separated word, even when using "-nargs=1"
        CmdLine         the entire command line
        CursorPos       the cursor position in it (byte index)
 The function may use these for determining context.  For the "custom"