Fix: branch and diff disappearing with diagnostics.goto_next())

I've added a workaround to re sync those components when they
go out of sync . Until upstream issue is addressed this should
prevent this issue from occurring in lualine.

lua/lualine/components/branch.lua

@@ -8,6 +8,7 @@ Branch.git_branch = ''
 Branch.sep = package.config:sub(1, 1)
 -- event watcher to watch head file
 Branch.file_changed = vim.loop.new_fs_event()
+Branch.active_bufnr = '0'
 local branch_cache = {} -- stores last known branch for a buffer
 -- Initilizer
 Branch.new = function(self, options, child)
@@ -23,6 +24,12 @@ Branch.new = function(self, options, child)
 end
 
 Branch.update_status = function(_, is_focused)
+  if Branch.active_bufnr ~= vim.g.actual_curbuf then
+    -- Workaround for https://github.com/hoob3rt/lualine.nvim/issues/286
+    -- See upstream issue https://github.com/neovim/neovim/issues/15300
+    -- Diff is out of sync re sync it.
+    Branch.update_branch()
+  end
   if not is_focused then return branch_cache[vim.fn.bufnr()] or '' end
   return Branch.git_branch
 end
@@ -79,6 +86,7 @@ end
 
 -- Update branch
 function Branch.update_branch()
+  Branch.active_bufnr = tostring(vim.fn.bufnr())
   Branch.file_changed:stop()
   local git_dir = Branch.find_git_dir()
   if git_dir and #git_dir > 0 then

lua/lualine/components/diff.lua

@@ -14,6 +14,7 @@ Diff.git_diff = nil
 Diff.diff_output_cache = {}
 -- variable to store git_diff job
 Diff.diff_job = nil
+Diff.active_bufnr = '0'
 -- default colors
 Diff.default_colors = {
   added = '#f0e130',
@@ -109,12 +110,19 @@ Diff.new = function(self, options, child)
     utils.define_autocmd('BufEnter', "lua require'lualine.components.diff'.update_diff_args()")
     utils.define_autocmd('BufWritePost', "lua require'lualine.components.diff'.update_git_diff()")
   end
+  Diff.update_diff_args()
 
   return new_instance
 end
 
 -- Function that runs everytime statusline is updated
 Diff.update_status = function(self, is_focused)
+  if Diff.active_bufnr ~= vim.g.actual_curbuf then
+    -- Workaround for https://github.com/hoob3rt/lualine.nvim/issues/286
+    -- See upstream issue https://github.com/neovim/neovim/issues/15300
+    -- Diff is out of sync re sync it.
+    Diff.update_diff_args()
+  end
   local git_diff = Diff.git_diff
   if self.options.source then
     git_diff = self.options.source()
@@ -195,6 +203,7 @@ end
 -- Updates the job args
 function Diff.update_diff_args()
   -- Donn't show git diff when current buffer doesn't have a filename
+  Diff.active_bufnr = tostring(vim.fn.bufnr())
   if #vim.fn.expand('%') == 0 then
     Diff.diff_args = nil;
     Diff.git_diff = nil;