runtime(doc): Improve command-line completion docs (#13331)

* Improve command-line completion docs

Add more details about 'ignorecase' and its effect on cmdline
completion.

Make sure keys used in wildmenu are properly documented and linked in the
keys' documentation entries, and in `:h index` for proper
cross-referencing, as wildmenu popup is slightly different from
insert-mode popup menu.

* Fix docs typos

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

3 files changed, 49 insertions, 19 deletions

diff --git a/runtime/doc/cmdline.txt b/runtime/doc/cmdline.txt
index 9493658ed5..6d58d63873 100644
--- a/runtime/doc/cmdline.txt
+++ b/runtime/doc/cmdline.txt
@@ -90,9 +90,11 @@ CTRL-SHIFT-Q	Works just like CTRL-V, unless |modifyOtherKeys| is active,
 		In the GUI the |key-notation| is inserted without simplifying.
 
 							*c_<Left>* *c_Left*
-<Left>		cursor left
+<Left>		cursor left.  See 'wildmenu' for behavior during wildmenu
+		completion mode.
 							*c_<Right>* *c_Right*
-<Right>		cursor right
+<Right>		cursor right.  See 'wildmenu' for behavior during wildmenu
+		completion mode.
 							*c_<S-Left>*
 <S-Left> or <C-Left>					*c_<C-Left>*
 		cursor one WORD left
@@ -102,7 +104,8 @@ CTRL-SHIFT-Q	Works just like CTRL-V, unless |modifyOtherKeys| is active,
 CTRL-B or <Home>				*c_CTRL-B* *c_<Home>* *c_Home*
 		cursor to beginning of command-line
 CTRL-E or <End>					*c_CTRL-E* *c_<End>* *c_End*
-		cursor to end of command-line
+		cursor to end of command-line.  See 'wildmenu' for behavior
+		during wildmenu completion mode.
 
 							*c_<LeftMouse>*
 <LeftMouse>	Move the cursor to the position of the mouse click.
@@ -237,6 +240,7 @@ CTRL-\ e {expr}						*c_CTRL-\_e*
 CTRL-Y		When there is a modeless selection, copy the selection into
 		the clipboard. |modeless-selection|
 		If there is no selection CTRL-Y is inserted as a character.
+		See 'wildmenu' for behavior during wildmenu completion mode.
 
 CTRL-M or CTRL-J		*c_CTRL-M* *c_CTRL-J* *c_<NL>* *c_<CR>* *c_CR*
 <CR> or <NL>	start entered command
@@ -252,12 +256,14 @@ CTRL-C		quit command-line without executing
 
 							*c_<Up>* *c_Up*
 <Up>		recall older command-line from history, whose beginning
-		matches the current command-line (see below).
+		matches the current command-line (see below).  See 'wildmenu'
+		for behavior during wildmenu completion mode.
 		{not available when compiled without the |+cmdline_hist|
 		feature}
 							*c_<Down>* *c_Down*
 <Down>		recall more recent command-line from history, whose beginning
-		matches the current command-line (see below).
+		matches the current command-line (see below).  See 'wildmenu'
+		for behavior during wildmenu completion mode.
 		{not available when compiled without the |+cmdline_hist|
 		feature}
 
@@ -463,11 +469,16 @@ When repeating 'wildchar' or CTRL-N you cycle through the matches, eventually
 ending up back to what was typed.  If the first match is not what you wanted,
 you can use <S-Tab> or CTRL-P to go straight back to what you typed.
 
-The 'wildignorecase' option can be set to ignore case in filenames.
-
 The 'wildmenu' option can be set to show the matches just above the command
 line.
 
+The 'wildoptions' option provides additional configuration to use a popup menu
+for 'wildmenu', and to use fuzzy matching.
+
+The 'wildignorecase' option can be set to ignore case in filenames.  For
+completing other texts (e.g. command names), the 'ignorecase' option is used
+instead (fuzzy matching always ignores case, however).
+
 If you like tcsh's autolist completion, you can use this mapping:
 	:cnoremap X <C-L><C-D>
 (Where X is the command key to use, <C-L> is CTRL-L and <C-D> is CTRL-D)
diff --git a/runtime/doc/index.txt b/runtime/doc/index.txt
index a302c59fe9..e7e99e2ec0 100644
--- a/runtime/doc/index.txt
+++ b/runtime/doc/index.txt
@@ -1112,6 +1112,22 @@ tag		command		action in Command-line editing mode	~
 |c_<Insert>|	<Insert>	toggle insert/overstrike mode
 |c_<LeftMouse>|	<LeftMouse>	cursor at mouse click
 
+commands in wildmenu mode (see 'wildmenu')
+
+		<Up>		move up to parent / select the previous match
+		<Down>		move down to submenu / select the next match
+		<Left>		select the previous match / move up to parent
+		<Down>		select the next match / move down to submenu
+		<CR>		move into submenu when doing menu completion
+		other		stop completion and insert the typed character
+
+commands in wildmenu mode with 'wildoptions' set to "pum"
+
+		CTRL-E		stop completion and go back to original text
+		CTRL-Y		accept selected match and stop completion
+		<PageUp>	select a match several entries back
+		<PageDown>	select a match several entries forward
+
 ==============================================================================
 5. Terminal-Job mode				*terminal-job-index*
 
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index cfef59de60..502e77ba1f 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -4440,8 +4440,8 @@ A jump table for the options with a short description can be found at |Q_op|.
 			*'ignorecase'* *'ic'* *'noignorecase'* *'noic'*
 'ignorecase' 'ic'	boolean	(default off)
 			global
-	Ignore case in search patterns.  Also used when searching in the tags
-	file.
+	Ignore case in search patterns, |cmdline-completion|, when
+	searching in the tags file, and non-|Vim9| |expr-==|.
 	Also see 'smartcase' and 'tagcase'.
 	Can be overruled by using "\c" or "\C" in the pattern, see
 	|/ignorecase|.
@@ -9314,29 +9314,32 @@ A jump table for the options with a short description can be found at |Q_op|.
 	as needed.
 	The "wildmenu" mode is abandoned when a key is hit that is not used
 	for selecting a completion.
-	While the "wildmenu" is active, not using the popup menu, the
-	following keys have special meanings:
-
-	<Left> <Right>	- select previous/next match (like CTRL-P/CTRL-N)
-	<Down>		- in filename/menu name completion: move into a
-			  subdirectory or submenu.
+	While the "wildmenu" is active, the following keys have special
+	meanings:
+	CTRL-P		- go to the previous entry
+	CTRL-N		- go to the next entry
 	<CR>		- in menu completion, when the cursor is just after a
 			  dot: move into a submenu.
+
+	When not using the popup menu for command line completion, the
+	following keys have special meanings:
+	<Left> <Right>	- select previous/next match (like CTRL-P/CTRL-N)
 	<Up>		- in filename/menu name completion: move up into
 			  parent directory or parent menu.
+	<Down>		- in filename/menu name completion: move into a
+			  subdirectory or submenu.
 
 	When using the popup menu for command line completion, the following
 	keys have special meanings:
-	<Down>		- select next match (like CTRL-N)
+	<Up> <Down>	- select previous/next match (like CTRL-P/CTRL-N)
 	<Left>		- in filename/menu name completion: move up into
 			  parent directory or parent menu.
 	<Right>		- in filename/menu name completion: move into a
 			  subdirectory or submenu.
-	<Up>		- select previous match (like CTRL-P)
+	<PageUp>	- Select a match several entries back, but don't insert it.
+	<PageDown>	- Select a match several entries further, but don't insert it.
 	CTRL-E		- end completion, go back to what was there before
 			  selecting a match.
-	CTRL-N		- go to the next entry
-	CTRL-P		- go to the previous entry
 	CTRL-Y		- accept the currently selected match and stop
 			  completion.