feat(blame): set filetype to gitsigns.blame

Resolves #1049

lua/gitsigns/blame.lua

@@ -253,6 +253,7 @@ M.blame = function()
   local blm_bo = vim.bo[blm_bufnr]
   blm_bo.buftype = 'nofile'
   blm_bo.modifiable = false
+  blm_bo.filetype = 'gitsigns.blame'
 
   local blm_wlo = vim.wo[blm_win][0]
   blm_wlo.foldcolumn = '0'

lua/gitsigns/cache.lua

@@ -19,7 +19,7 @@ local M = {
 --- @field staged_diffs?      Gitsigns.Hunk.Hunk[]
 --- @field gitdir_watcher?    uv.uv_fs_event_t
 --- @field git_obj            Gitsigns.GitObj
---- @field blame?             table<integer,Gitsigns.BlameInfo|false?>
+--- @field blame?             table<integer,Gitsigns.BlameInfo?>
 local CacheEntry = M.CacheEntry
 
 function CacheEntry:get_rev_bufname(rev)

lua/gitsigns/manager.lua

@@ -79,7 +79,7 @@ local function apply_win_signs(bufnr, top, bot, clear)
   end
 end
 
---- @param blame table<integer,Gitsigns.BlameInfo|false?>?
+--- @param blame table<integer,Gitsigns.BlameInfo?>?
 --- @param first integer
 --- @param last_orig integer
 --- @param last_new integer
@@ -91,11 +91,11 @@ local function on_lines_blame(blame, first, last_orig, last_new)
   if last_new < last_orig then
     util.list_remove(blame, last_new + 1, last_orig)
   elseif last_new > last_orig then
-    util.list_insert(blame, last_orig + 1, last_new, false)
+    util.list_insert(blame, last_orig + 1, last_new)
   end
 
   for i = first + 1, last_new do
-    blame[i] = false
+    blame[i] = nil
   end
 end
 

lua/gitsigns/util.lua

@@ -327,7 +327,7 @@ end
 ---@param first integer
 ---@param last integer
 function M.list_remove(t, first, last)
-  local n = #t
+  local n = table.maxn(t)
   for i = 0, n - first do
     t[first + i] = t[last + 1 + i]
     t[last + 1 + i] = nil
@@ -347,7 +347,7 @@ end
 ---@param last integer
 ---@param v any
 function M.list_insert(t, first, last, v)
-  local n = #t
+  local n = table.maxn(t)
 
   -- Shift table forward
   for i = n - first, 0, -1 do