fix(blame): fix possible race condition

It is possible for the buffer to change during the async function. To avoid this, before applying the extmark, check that the cursor is in the same position. If it is the extmark should be ok to apply and at the very least will avoid the `line value outside range` error. Fixes #312
lewis6991 · Oct 18, 2021 · 2a1f3e6 · jdrouhard · Oct 18, 2021 · lewis6991
1 parent 02b9799
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diff --git a/lua/gitsigns/current_line_blame.lua b/lua/gitsigns/current_line_blame.lua
diff --git a/teal/gitsigns/current_line_blame.tl b/teal/gitsigns/current_line_blame.tl
@@ -28,6 +28,7 @@ M.reset = function(bufnr: integer)
   pcall(api.nvim_buf_del_var, bufnr, 'gitsigns_blame_line_dict')
 end
 
+-- Update function, must be called in async context
 M.update = void(function()
   M.reset()
 
@@ -49,6 +50,13 @@ M.update = void(function()
 
   M.reset(bufnr)
 
+  local lnum1 = api.nvim_win_get_cursor(0)[1]
+  if lnum ~= lnum1 or not api.nvim_buf_is_loaded(bufnr) then
+    -- Cursor has moved during events; abort
+    -- Buffer is no longer loaded; abort
+    return
+  end
+
   api.nvim_buf_set_var(bufnr, 'gitsigns_blame_line_dict', result)
   if config.current_line_blame_opts.virt_text then
     api.nvim_buf_set_extmark(bufnr, namespace, lnum-1, 0, {