vim-patch:9.0.1710: scrolloff options work slightly different

Problem: sidescrolloff and scrolloff options work slightly
         different than other global-local options
Solution: Make it behave consistent for all global-local options

It was noticed, that sidescrolloff and scrolloff options behave
differently in comparison to other global-local window options like
'listchars'

So make those two behave like other global-local options. Also add some
extra documentation for a few special local-window options.

Add a few tests to make sure all global-local window options behave
similar

closes: vim/vim#12956
closes: vim/vim#12643

https://github.com/vim/vim/commit/4a8eb6e7a9df10f79bf95301ced012f0d6a13088

Co-authored-by: Christian Brabandt <cb@256bit.org>

7 files changed, 162 insertions, 17 deletions

diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index f04fb2fb51..eea9f2cf4b 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -189,6 +189,8 @@ opt+=val" the expansion is done before the adding or removing.
 
 Handling of local options			*local-options*
 
+Note: The following also applies to |global-local| options.
+
 Some of the options only apply to a window or buffer.  Each window or buffer
 has its own copy of this option, thus each can have its own value.  This
 allows you to set 'list' in one window but not in another.  And set
@@ -238,6 +240,30 @@ The options local to a window are remembered for each buffer.  This also
 happens when the buffer is not loaded, but they are lost when the buffer is
 wiped out |:bwipe|.
 
+Special local window options			*special-local-window-option*
+
+The following local window options won't be copied over when new windows are
+created, thus they behave slightly differently:
+
+	Option		Reason	~
+	'previewwindow'	there can only be a single one
+	'scroll'	specific to existing window
+	'winfixheight'	specific to existing window
+	'winfixwidth'	specific to existing window
+
+Special local buffer options			*special-local-buffer-option*
+
+The following local buffer options won't be copied over when new buffers are
+created, thus they behave slightly differently:
+
+	Option		Reason	~
+	'filetype'	explicitly set by autocommands
+	'syntax'	explicitly set by autocommands
+	'bufhidden'	denote |special-buffers|
+	'buftype'	denote |special-buffers|
+	'readonly'	will be detected automatically
+	'modified'	will be detected automatically
+
 							*:setl* *:setlocal*
 :setl[ocal][!] ...	Like ":set" but set only the value local to the
 			current buffer or window.  Not all options have a
@@ -311,7 +337,6 @@ used.  Thus it does the same as: >
 Note: In the future more global options can be made |global-local|.  Using
 ":setlocal" on a global option might work differently then.
 
-
 						*option-value-function*
 Some options ('completefunc', 'omnifunc', 'operatorfunc', 'quickfixtextfunc',
 'tagfunc' and 'thesaurusfunc') are set to a function name or a function
@@ -1070,7 +1095,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 						*'bufhidden'* *'bh'*
 'bufhidden' 'bh'	string	(default "")
-			local to buffer
+			local to buffer  |special-local-buffer-option|
 	This option specifies what happens when a buffer is no longer
 	displayed in a window:
 	  <empty>	follow the global 'hidden' option
@@ -1102,7 +1127,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 						*'buftype'* *'bt'* *E382*
 'buftype' 'bt'		string	(default "")
-			local to buffer
+			local to buffer  |special-local-buffer-option|
 	The value of this option specifies the type of a buffer:
 	  <empty>	normal buffer
 	  acwrite	buffer will always be written with |BufWriteCmd|s
@@ -2408,7 +2433,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 						*'filetype'* *'ft'*
 'filetype' 'ft'		string	(default "")
-			local to buffer
+			local to buffer  |special-local-buffer-option|
 	When this option is set, the FileType autocommand event is triggered.
 	All autocommands that match with the value of this option will be
 	executed.  Thus the value of 'filetype' is used in place of the file
@@ -4084,7 +4109,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 				*'modified'* *'mod'* *'nomodified'* *'nomod'*
 'modified' 'mod'	boolean	(default off)
-			local to buffer
+			local to buffer  |special-local-buffer-option|
 	When on, the buffer is considered to be modified.  This option is set
 	when:
 	1. A change was made to the text since it was last written.  Using the
@@ -4532,7 +4557,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 		*'previewwindow'* *'pvw'* *'nopreviewwindow'* *'nopvw'* *E590*
 'previewwindow' 'pvw'	boolean	(default off)
-			local to window
+			local to window  |special-local-window-option|
 	Identifies the preview window.  Only one window can have this option
 	set.  It's normally not set directly, but by using one of the commands
 	|:ptag|, |:pedit|, etc.
@@ -4602,7 +4627,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 				*'readonly'* *'ro'* *'noreadonly'* *'noro'*
 'readonly' 'ro'		boolean	(default off)
-			local to buffer
+			local to buffer  |special-local-buffer-option|
 	If on, writes fail unless you use a '!'.  Protects you from
 	accidentally overwriting a file.  Default on when Vim is started
 	in read-only mode ("vim -R") or when the executable is called "view".
@@ -4864,7 +4889,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 						*'scroll'* *'scr'*
 'scroll' 'scr'		number	(default half the window height)
-			local to window
+			local to window  |special-local-window-option|
 	Number of lines to scroll with CTRL-U and CTRL-D commands.  Will be
 	set to half the number of lines in the window when the window size
 	changes.  This may happen when enabling the |status-line| or
@@ -6214,7 +6239,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 						*'syntax'* *'syn'*
 'syntax' 'syn'		string	(default "")
-			local to buffer
+			local to buffer  |special-local-buffer-option|
 	When this option is set, the syntax with this name is loaded, unless
 	syntax highlighting has been switched off with ":syntax off".
 	Otherwise this option does not always reflect the current syntax (the
@@ -7081,7 +7106,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 			*'winfixheight'* *'wfh'* *'nowinfixheight'* *'nowfh'*
 'winfixheight' 'wfh'	boolean	(default off)
-			local to window
+			local to window  |special-local-window-option|
 	Keep the window height when windows are opened or closed and
 	'equalalways' is set.  Also for |CTRL-W_=|.  Set by default for the
 	|preview-window| and |quickfix-window|.
@@ -7089,7 +7114,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 			*'winfixwidth'* *'wfw'* *'nowinfixwidth'* *'nowfw'*
 'winfixwidth' 'wfw'	boolean	(default off)
-			local to window
+			local to window  |special-local-window-option|
 	Keep the window width when windows are opened or closed and
 	'equalalways' is set.  Also for |CTRL-W_=|.
 	The width may be changed anyway when running out of room.
diff --git a/scripts/gen_eval_files.lua b/scripts/gen_eval_files.lua
index 9bc9e99c46..2990eef069 100755
--- a/scripts/gen_eval_files.lua
+++ b/scripts/gen_eval_files.lua
@@ -542,6 +542,36 @@ local function scope_to_doc(s)
   return 'global or '..m[s[2]]..' |global-local|'
 end
 
+-- @param o vim.option_meta
+-- @return string
+local function scope_more_doc(o)
+  if
+    vim.list_contains({
+      'previewwindow',
+      'scroll',
+      'winfixheight',
+      'winfixwidth',
+    }, o.full_name)
+  then
+    return '  |special-local-window-option|'
+  end
+
+  if
+    vim.list_contains({
+      'bufhidden',
+      'buftype',
+      'filetype',
+      'modified',
+      'readonly',
+      'syntax',
+    }, o.full_name)
+  then
+    return '  |special-local-buffer-option|'
+  end
+
+  return ''
+end
+
 --- @return table<string,vim.option_meta>
 local function get_option_meta()
   local opts = require('src/nvim/options').options
@@ -624,7 +654,7 @@ local function render_option_doc(_f, opt, write)
     write(string.format('%s\t%s', name_str, otype))
   end
 
-  write('\t\t\t'..scope_to_doc(opt.scope))
+  write('\t\t\t'..scope_to_doc(opt.scope)..scope_more_doc(opt))
   for _, l in ipairs(split(opt.desc)) do
     if l == '<' or l:match('^<%s') then
       write(l)
diff --git a/src/nvim/buffer_defs.h b/src/nvim/buffer_defs.h
index 0a7c742798..c94dbfa7fb 100644
--- a/src/nvim/buffer_defs.h
+++ b/src/nvim/buffer_defs.h
@@ -230,6 +230,10 @@ typedef struct {
 #define w_p_crb_save w_onebuf_opt.wo_crb_save
   char *wo_scl;
 #define w_p_scl w_onebuf_opt.wo_scl    // 'signcolumn'
+  long wo_siso;
+#define w_p_siso w_onebuf_opt.wo_siso  // 'sidescrolloff' local value
+  long wo_so;
+#define w_p_so w_onebuf_opt.wo_so      // 'scrolloff' local value
   char *wo_winhl;
 #define w_p_winhl w_onebuf_opt.wo_winhl    // 'winhighlight'
   char *wo_lcs;
@@ -1321,8 +1325,6 @@ struct window_S {
   uint32_t w_p_fdt_flags;           // flags for 'foldtext'
   int *w_p_cc_cols;                 // array of columns to highlight or NULL
   uint8_t w_p_culopt_flags;         // flags for cursorline highlighting
-  long w_p_siso;                    // 'sidescrolloff' local value
-  long w_p_so;                      // 'scrolloff' local value
 
   int w_briopt_min;                 // minimum width for breakindent
   int w_briopt_shift;               // additional shift for breakindent
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 4ca52baa78..56881cbe58 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -4702,6 +4702,8 @@ void copy_winopt(winopt_T *from, winopt_T *to)
   to->wo_sms = from->wo_sms;
   to->wo_crb = from->wo_crb;
   to->wo_crb_save = from->wo_crb_save;
+  to->wo_siso = from->wo_siso;
+  to->wo_so = from->wo_so;
   to->wo_spell = from->wo_spell;
   to->wo_cuc = from->wo_cuc;
   to->wo_cul = from->wo_cul;
diff --git a/src/nvim/window.c b/src/nvim/window.c
index 175a79568c..6ff9e07260 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -5132,8 +5132,8 @@ static win_T *win_alloc(win_T *after, bool hidden)
   new_wp->w_ns_hl = -1;
 
   // use global option for global-local options
-  new_wp->w_p_so = -1;
-  new_wp->w_p_siso = -1;
+  new_wp->w_allbuf_opt.wo_so = new_wp->w_p_so = -1;
+  new_wp->w_allbuf_opt.wo_siso = new_wp->w_p_siso = -1;
 
   // We won't calculate w_fraction until resizing the window
   new_wp->w_fraction = 0;
diff --git a/test/functional/lua/vim_spec.lua b/test/functional/lua/vim_spec.lua
index 35e87b71da..9338e95d10 100644
--- a/test/functional/lua/vim_spec.lua
+++ b/test/functional/lua/vim_spec.lua
@@ -1548,7 +1548,7 @@ describe('lua stdlib', function()
     eq(100, funcs.luaeval "vim.wo.scrolloff")
     exec_lua [[
     vim.wo[0][0].scrolloff = 200
-    vim.cmd "split"
+    vim.cmd "enew"
     ]]
     eq(100, funcs.luaeval "vim.wo.scrolloff")
   end)
diff --git a/test/old/testdir/test_options.vim b/test/old/testdir/test_options.vim
index aabb11a76a..12a262f2ad 100644
--- a/test/old/testdir/test_options.vim
+++ b/test/old/testdir/test_options.vim
@@ -1682,4 +1682,90 @@ func Test_string_option_revert_on_failure()
   bw!
 endfunc
 
+func Test_set_option_window_global_local()
+  new Xbuffer1
+  let [ _gso, _lso ] = [ &g:scrolloff, &l:scrolloff ]
+  setlocal scrolloff=2
+  setglobal scrolloff=3
+  setl modified
+  " A new buffer has its own window-local options
+  hide enew
+  call assert_equal(-1, &l:scrolloff)
+  call assert_equal(3, &g:scrolloff)
+  " A new window opened with its own buffer-local options
+  new
+  call assert_equal(-1, &l:scrolloff)
+  call assert_equal(3, &g:scrolloff)
+  " Re-open Xbuffer1 and it should use
+  " the previous set window-local options
+  b Xbuffer1
+  call assert_equal(2, &l:scrolloff)
+  call assert_equal(3, &g:scrolloff)
+  bw!
+  bw!
+  let &g:scrolloff =  _gso
+endfunc
+
+func GetGlobalLocalWindowOptions()
+  new
+  sil! r $VIMRUNTIME/doc/options.txt
+  " Filter for global or local to window
+  v/^'.*'.*\n.*global or local to window |global-local/d
+  " get option value and type
+  sil %s/^'\([^']*\)'.*'\s\+\(\w\+\)\s\+(default \%(\(".*"\|\d\+\|empty\)\).*/\1 \2 \3/g
+  " sil %s/empty/""/g
+  " split the result
+  " let result=getline(1,'$')->map({_, val -> split(val, ' ')})
+  let result = getline(1, '$')->map({_, val -> matchlist(val, '\([^ ]\+\) \+\([^ ]\+\) \+\(.*\)')[1:3]})
+  bw!
+  return result
+endfunc
+
+func Test_set_option_window_global_local_all()
+  new Xbuffer2
+
+  let optionlist = GetGlobalLocalWindowOptions()
+  for [opt, type, default] in optionlist
+    let _old = eval('&g:' .. opt)
+    if type == 'string'
+      if opt == 'fillchars'
+        exe 'setl ' .. opt .. '=vert:+'
+        exe 'setg ' .. opt .. '=vert:+,fold:+'
+      elseif opt == 'listchars'
+        exe 'setl ' .. opt .. '=tab:>>'
+        exe 'setg ' .. opt .. '=tab:++'
+      elseif opt == 'virtualedit'
+        exe 'setl ' .. opt .. '=all'
+        exe 'setg ' .. opt .. '=block'
+      else
+        exe 'setl ' .. opt .. '=Local'
+        exe 'setg ' .. opt .. '=Global'
+      endif
+    elseif type == 'number'
+      exe 'setl ' .. opt .. '=5'
+      exe 'setg ' .. opt .. '=10'
+    endif
+    setl modified
+    hide enew
+    if type == 'string'
+      call assert_equal('', eval('&l:' .. opt))
+      if opt == 'fillchars'
+        call assert_equal('vert:+,fold:+', eval('&g:' .. opt), 'option:' .. opt)
+      elseif opt == 'listchars'
+        call assert_equal('tab:++', eval('&g:' .. opt), 'option:' .. opt)
+      elseif opt == 'virtualedit'
+        call assert_equal('block', eval('&g:' .. opt), 'option:' .. opt)
+      else
+        call assert_equal('Global', eval('&g:' .. opt), 'option:' .. opt)
+      endif
+    elseif type == 'number'
+      call assert_equal(-1, eval('&l:' .. opt), 'option:' .. opt)
+      call assert_equal(10, eval('&g:' .. opt), 'option:' .. opt)
+    endif
+    bw!
+    exe 'let &g:' .. opt .. '=' .. default
+  endfor
+  bw!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab