vim-patch:8.2.3969: value of MAXCOL not available in Vim script

Problem:    Value of MAXCOL not available in Vim script.
Solution:   Add v:maxcol. (Naohiro Ono, closes vim/vim#9451)

https://github.com/vim/vim/commit/56200eed62e59ad831f6564dcafe346e6f97ac20

The variable is always 2147483647, but introducing it makes functions
easier to document.

Co-authored-by: naohiro ono <obcat@icloud.com>

2 files changed, 18 insertions, 7 deletions

diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index 7fab2ac6ff..dd5b77e8ac 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -2890,6 +2890,9 @@ getcharpos({expr})
 		Get the position for String {expr}. Same as |getpos()| but the
 		column number in the returned List is a character index
 		instead of a byte index.
+		If |getpos()| returns a very large column number, equal to
+		|v:maxcol|, then getcharpos() will return the character index
+		of the last character.
 
 		Example:
 		With the cursor on '세' in line 5 with text "여보세요": >
@@ -3064,10 +3067,11 @@ getcompletion({pat}, {type} [, {filtered}])		*getcompletion()*
 							*getcurpos()*
 getcurpos([{winid}])
 		Get the position of the cursor.  This is like getpos('.'), but
-		includes an extra "curswant" in the list:
+		includes an extra "curswant" item in the list:
 		    [0, lnum, col, off, curswant] ~
 		The "curswant" number is the preferred column when moving the
-		cursor vertically.  Also see |getcursorcharpos()| and
+		cursor vertically.  After |$| command it will be a very large
+		number equal to |v:maxcol|.  Also see |getcursorcharpos()| and
 		|getpos()|.
 		The first "bufnum" item is always zero. The byte position of
 		the cursor is returned in "col". To get the character
@@ -3389,12 +3393,12 @@ getpos({expr})	Get the position for String {expr}.  For possible values of
 		character.
 		Note that for '< and '> Visual mode matters: when it is "V"
 		(visual line mode) the column of '< is zero and the column of
-		'> is a large number.
+		'> is a large number equal to |v:maxcol|.
 		The column number in the returned List is the byte position
 		within the line. To get the character position in the line,
 		use |getcharpos()|.
-		The column number can be very large, e.g. 2147483647, in which
-		case it means "after the end of the line".
+		A very large column number equal to |v:maxcol| can be returned,
+		in which case it means "after the end of the line".
 		If {expr} is invalid, returns a list with all zeros.
 		This can be used to save and restore the position of a mark: >
 			let save_a_mark = getpos("'a")
@@ -9407,10 +9411,14 @@ winsaveview()	Returns a |Dictionary| that contains information to restore
 		The return value includes:
 			lnum		cursor line number
 			col		cursor column (Note: the first column
-					zero, as opposed to what getpos()
+					zero, as opposed to what |getcurpos()|
 					returns)
 			coladd		cursor column offset for 'virtualedit'
-			curswant	column for vertical movement
+			curswant	column for vertical movement (Note:
+					the first column is zero, as opposed
+					to what |getcurpos()| returns).  After
+					|$| command it will be a very large
+					number equal to |v:maxcol|.
 			topline		first line in the window
 			topfill		filler lines, only in diff mode
 			leftcol		first column displayed; only used when
diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index d79b446986..51e26cc28b 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -1979,6 +1979,9 @@ v:lnum		Line number for the 'foldexpr' |fold-expr|, 'formatexpr',
 v:lua		Prefix for calling Lua functions from expressions.
 		See |v:lua-call| for more information.
 
+						*v:maxcol* *maxcol-variable*
+v:maxcol	Maximum line length.
+
 					*v:mouse_win* *mouse_win-variable*
 v:mouse_win	Window number for a mouse click obtained with |getchar()|.
 		First window has number 1, like with |winnr()|.  The value is