Subject: bug#60355: 29.0.60; Tree sitter incorrectly handles of PRED for treesit-defun-type-regexp

From: Wilhelm H Kirschbaum <[email-masked]>
Date: Tue, 27 Dec 2022 14:09:29 +0200

When `treesit-defun-type-regexp` is set with a cons cell (regexp . 
some-pred)
the following case does not get handled as expected when calling 
(end-of-defun):

```elixir
defmodule Example do
  def foo() do ; regexp match, pred match
  end

  ;; <point here>
  @impl true    ; regexp match, pred does not match
  def bar() do  ; regexp match, pred match
  end
  ;; <should jump to here>

  def baz() do
  end
end
;; <jumps to point here>
```

The function `treesit--things-around` only looks at the PRED after 
it searches forward and
would then not be aware of the non matching node.  The following 
change works for my case
where search-forward takes in the PRED, not just the regexp:

diff --git a/lisp/treesit.el b/lisp/treesit.el
index 2130cd0061..7997509f50 100644
--- a/lisp/treesit.el
+++ b/lisp/treesit.el
@@ -1776,7 +1776,13 @@ treesit--things-around
                             node "" nil nil t))
                        node))
          (result (list nil nil nil))
-         (pred (or pred (lambda (_) t))))
+         (pred (if (null pred)
+                (lambda (node)
+                  (string-match-p regexp (treesit-node-type 
node)))
+                (lambda (node)
+                  (and (string-match-p regexp (treesit-node-type 
node))
+                       (funcall pred node))))))
+
     ;; 1. Find previous and next sibling defuns.
     (cl-loop
      for idx from 0 to 1
@@ -1798,12 +1804,10 @@ treesit--things-around
      do (cl-loop for cursor = (when node
                                 (save-excursion
                                   (treesit-search-forward
-                                   node regexp backward 
                                    backward)))
+                                   node pred backward backward)))
                  then (treesit-node-parent cursor)
                  while cursor
-                 if (and (string-match-p
-                          regexp (treesit-node-type cursor))
-                         (funcall pred cursor)
+                 if (and (funcall pred cursor)
                          (funcall pos-pred cursor))
                  do (setf (nth idx result) cursor)))
     ;; 2. Find the parent defun.

Hope this makes sense,
Wilhelm

ps. Sorry about the email swapping, think it should be fixed now.