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: #12956
closes: #12643

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

runtime/doc/options.txt

@@ -252,6 +252,8 @@ 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
@@ -301,6 +303,30 @@ 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
@@ -374,7 +400,6 @@ 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', 'imactivatefunc', 'imstatusfunc', 'omnifunc',
 'operatorfunc', 'quickfixtextfunc', 'tagfunc' and 'thesaurusfunc') are set to
@@ -1449,7 +1474,7 @@ 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
@@ -1481,7 +1506,7 @@ 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
 	  nofile	buffer which is not related to a file and will not be
@@ -3408,7 +3433,7 @@ 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
@@ -5565,7 +5590,7 @@ 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
@@ -6136,7 +6161,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 					*'previewwindow'* *'nopreviewwindow'*
 					*'pvw'* *'nopvw'* *E590*
 'previewwindow' 'pvw'	boolean (default off)
-			local to window
+			local to window  |special-local-window-option|
 			{not available when compiled without the |+quickfix|
 			feature}
 	Identifies the preview window.  Only one window can have this option
@@ -6331,7 +6356,7 @@ 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".
@@ -6710,7 +6735,7 @@ 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
@@ -7972,7 +7997,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 						*'syntax'* *'syn'*
 'syntax' 'syn'		string	(default empty)
-			local to buffer
+			local to buffer  |special-local-buffer-option|
 			{not available when compiled without the |+syntax|
 			feature}
 	When this option is set, the syntax with this name is loaded, unless
@@ -9420,7 +9445,7 @@ 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|.
@@ -9428,7 +9453,7 @@ 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.

runtime/doc/tags

@@ -9708,6 +9708,8 @@ spec_chglog_format	pi_spec.txt	/*spec_chglog_format*
 spec_chglog_prepend	pi_spec.txt	/*spec_chglog_prepend*
 spec_chglog_release_info	pi_spec.txt	/*spec_chglog_release_info*
 special-buffers	windows.txt	/*special-buffers*
+special-local-buffer-option	options.txt	/*special-local-buffer-option*
+special-local-window-option	options.txt	/*special-local-window-option*
 specifies	vim9class.txt	/*specifies*
 speed-up	tips.txt	/*speed-up*
 spell	spell.txt	/*spell*

src/option.c

@@ -6652,6 +6652,8 @@ 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;
 #ifdef FEAT_SPELL
     to->wo_spell = from->wo_spell;
 #endif

src/structs.h

@@ -312,6 +312,10 @@ typedef struct
     char_u	*wo_scl;
 # define w_p_scl w_onebuf_opt.wo_scl	// 'signcolumn'
 #endif
+    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
 #ifdef FEAT_TERMINAL
     char_u	*wo_twk;
 # define w_p_twk w_onebuf_opt.wo_twk	// 'termwinkey'
@@ -3977,8 +3981,6 @@ struct window_S
     int		*w_p_cc_cols;	    // array of columns to highlight or NULL
     char_u	w_p_culopt_flags;   // flags for cursorline highlighting
 #endif
-    long	w_p_siso;	    // 'sidescrolloff' local value
-    long	w_p_so;		    // 'scrolloff' local value
 
 #ifdef FEAT_LINEBREAK
     int		w_briopt_min;	    // minimum width for breakindent

src/testdir/test_options.vim

@@ -1689,4 +1689,89 @@ 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, ' ')})
+  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

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1710,
 /**/
     1709,
 /**/

src/window.c

@@ -5546,8 +5546,8 @@ win_alloc(win_T *after, int hidden)
     new_wp->w_scbind_pos = 1;
 
     // use global option value 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;