emacs-31 062dcd2aead: Fix prev-adaptive-prefix anchor (bug#61314)

branch: emacs-31
commit 062dcd2aead00c3b47c14ff5b6c40313f7a775f5
Author: Yuan Fu <[email protected]>
Commit: Eli Zaretskii <[email protected]>

    Fix prev-adaptive-prefix anchor (bug#61314)
    
    * lisp/treesit.el (treesit-simple-indent-presets):
    Replace (match-beginning 1) with (skip-syntax-forward "-"), both
    returns the position of the beginning of the prefix, but
    skip-syntax-forward always works regardless whether
    adaptive-fill-regexp has a match group for the prefix.
---
 lisp/treesit.el | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/lisp/treesit.el b/lisp/treesit.el
index 7fa7df08194..1273e43b2fe 100644
--- a/lisp/treesit.el
+++ b/lisp/treesit.el
@@ -2559,9 +2559,11 @@ as the anchor.")
                          ;; has a prefix, indent to the beginning of
                          ;; prev line's prefix rather than the end of
                          ;; prev line's prefix. (Bug#61314).
-                         (or (and this-line-has-prefix
-                                  (match-beginning 1))
-                             (match-end 0)))))))
+                         (if this-line-has-prefix
+                             (progn
+                               (skip-syntax-forward "-")
+                               (point))
+                           (match-end 0)))))))
         (cons 'grand-parent
               (lambda (_n parent &rest _)
                 (treesit-node-start (treesit-node-parent parent))))