fix(api): nvim_set_option_value for global-local options

global-local window options need to be handled specially. When `win` is
given but `scope` is not, then we want to set the local version of the
option but not the global one, therefore we need to force
`scope='local'`.

Note this does not apply to window-local only options (e.g. 'number')

Example:

   nvim_set_option_value('scrolloff', 10, {})       -- global-local window option; set global value
   nvim_set_option_value('scrolloff', 20, {win=0})  -- global-local window option; set local value
   nvim_set_option_value('number', true, {})        -- local window option

is now equivalent to:

   nvim_set_option_value('scrolloff', 10, {})
   nvim_set_option_value('scrolloff', 20, {win=0, scope='local'})  -- changed from before
   nvim_set_option_value('number', true, {win=0})                  -- unchanged from before

Only the global-local option with a `win` provided gets forced to local
scope.

1 files changed, 7 insertions, 0 deletions

diff --git a/test/functional/lua/vim_spec.lua b/test/functional/lua/vim_spec.lua
index 44e65afc78..dfbcbbe688 100644
--- a/test/functional/lua/vim_spec.lua
+++ b/test/functional/lua/vim_spec.lua
@@ -1424,6 +1424,13 @@ describe('lua stdlib', function()
     vim.wo[1000].cole = 0
     ]]
     eq(0, funcs.luaeval "vim.wo[1000].cole")
+
+    -- Can handle global-local values
+    exec_lua [[vim.o.scrolloff = 100]]
+    exec_lua [[vim.wo.scrolloff = 200]]
+    eq(200, funcs.luaeval "vim.wo.scrolloff")
+    exec_lua [[vim.wo.scrolloff = -1]]
+    eq(100, funcs.luaeval "vim.wo.scrolloff")
   end)
 
   describe('vim.opt', function()