fix(view): wait for scheduled post_open work before returning

lua/diffview/scene/view.lua

@@ -188,6 +188,13 @@ function View:open()
   apply_diffopt(self)
   DiffviewGlobal.emitter:emit("view_opened", self)
   DiffviewGlobal.emitter:emit("view_enter", self)
+  -- Drain `post_open`'s scheduled entry setup before returning. Otherwise
+  -- typeahead after the command can reach a buffer whose diffview keymap
+  -- hasn't attached yet and falls through to native `:diffget` (see #262).
+  vim.wait(2000, function()
+    ---@diagnostic disable-next-line: undefined-field
+    return self.ready and self.cur_entry ~= nil
+  end)
 end
 
 ---@param opts? diffview.View.CloseOpts # Forwarded to subclass overrides; ignored at the base level.

lua/diffview/tests/functional/file_merge_view_spec.lua

@@ -249,4 +249,29 @@ describe("diffview.scene.views.diff.file_merge_view", function()
       os.remove(right)
     end)
   end)
+
+  -- Regression: `View:open` waits for the scheduled entry setup so
+  -- typeahead after `:DiffviewMergeFiles` reaches the real MERGED buffer
+  -- with its `Ndo` keymap attached (issue #262).
+  describe("FileMergeView:open (issue #262 race guard)", function()
+    it("populates `cur_entry` and `ready` before returning", function()
+      local output = tmpfile("<<<<<<< HEAD\nc\n=======\ne\n>>>>>>> what\n")
+      local base = tmpfile("a\n")
+      local left = tmpfile("c\n")
+      local right = tmpfile("e\n")
+
+      local view = lib.diffview_merge_files({ output, base, left, right })
+      assert.is_not_nil(view)
+      view:open()
+
+      assert.is_true(view.ready)
+      assert.is_not_nil(view.cur_entry)
+
+      helpers.close_view(view)
+      os.remove(output)
+      os.remove(base)
+      os.remove(left)
+      os.remove(right)
+    end)
+  end)
 end)

lua/diffview/tests/functional/open_race_guard_spec.lua

@@ -0,0 +1,84 @@
+-- Regression: `View:open` waits for the scheduled entry setup so typeahead
+-- after `:DiffviewOpen` on a conflict reaches the real file buffer with its
+-- `Ndo` keymap attached (issue #262). Mirrors the `FileMergeView` case in
+-- `file_merge_view_spec.lua` from the `DiffView` / git-adapter side.
+local config = require("diffview.config")
+local helpers = require("diffview.tests.helpers")
+
+local DiffView = require("diffview.scene.views.diff.diff_view").DiffView
+local EventEmitter = require("diffview.events").EventEmitter
+local GitAdapter = require("diffview.vcs.adapters.git").GitAdapter
+local GitRev = require("diffview.vcs.adapters.git.rev").GitRev
+local RevType = require("diffview.vcs.rev").RevType
+
+local run = helpers.run
+
+local function make_conflict_repo()
+  local repo = helpers.init_repo()
+  local path = repo .. "/file.txt"
+  local function write(content)
+    local f = assert(io.open(path, "w"))
+    f:write(content)
+    f:close()
+  end
+
+  write("a\n")
+  run({ "git", "add", "file.txt" }, repo)
+  run({ "git", "-c", "commit.gpgsign=false", "commit", "-q", "-m", "base" }, repo)
+
+  -- `init.defaultBranch` may be `main` or `master`; read it back.
+  local base_branch = run({ "git", "symbolic-ref", "--short", "HEAD" }, repo)
+
+  run({ "git", "checkout", "-q", "-b", "ours" }, repo)
+  write("c\n")
+  run({ "git", "-c", "commit.gpgsign=false", "commit", "-q", "-am", "ours" }, repo)
+  run({ "git", "checkout", "-q", base_branch }, repo)
+  run({ "git", "checkout", "-q", "-b", "theirs" }, repo)
+  write("e\n")
+  run({ "git", "-c", "commit.gpgsign=false", "commit", "-q", "-am", "theirs" }, repo)
+  run({ "git", "checkout", "-q", "ours" }, repo)
+  run({ "git", "merge", "theirs" }, repo, { allow_nonzero = true })
+
+  return repo
+end
+
+describe("DiffView:open (issue #262 race guard)", function()
+  local orig_emitter, original_config
+
+  before_each(function()
+    orig_emitter = DiffviewGlobal.emitter
+    DiffviewGlobal.emitter = EventEmitter()
+    original_config = vim.deepcopy(config.get_config())
+    config.get_config().use_icons = false
+  end)
+
+  after_each(function()
+    DiffviewGlobal.emitter = orig_emitter
+    config.setup(original_config)
+  end)
+
+  it("populates `cur_entry` and `ready` before returning on a git conflict", function()
+    local repo = make_conflict_repo()
+    local view
+
+    local ok, err = pcall(function()
+      view = DiffView({
+        adapter = GitAdapter({ toplevel = repo, cpath = repo, path_args = {} }),
+        rev_arg = nil,
+        path_args = {},
+        left = GitRev(RevType.STAGE, 0),
+        right = GitRev(RevType.LOCAL),
+        options = {},
+      })
+      view:open()
+      assert.is_true(view.ready)
+      assert.is_not_nil(view.cur_entry)
+    end)
+
+    helpers.close_view(view)
+    helpers.cleanup_repo(repo)
+    if not ok then
+      error(err)
+    end
+  end)
+end)