From: Yuan Fu <casouri@gmail.com>
Date: Thu, 13 Mar 2025 07:33:47 +0000 (-0700)
Subject: Fix treesit-parser-create behavior regarding indirect buffers
X-Git-Tag: archive/raspbian/1%30.2+1-2+rpi1^2~2^2~24^2~204
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success/%22http:/www.example.com/cgi/success?a=commitdiff_plain;h=defc55bb6f954276a1cb9e3b5c50251ba5e5b40f;p=emacs.git

Fix treesit-parser-create behavior regarding indirect buffers

The previous fix fixed the problem that treesit-parser-create
always use the current buffer, but that introduce another subtle
problem: if an indirect buffer creates a parser, the parser
saves the base buffer rather than the indirect buffer.  In Emacs
29, if you create a parser in an indirect buffer, the parser
saves the indirect buffer.  This change of behavior breaks some
existing use-cases for people using indirect buffer with
tree-sitter.

In Emacs 31, indirect buffers and base buffer get their own
parser list, so this problem doesn't exist anymore.  The fix is
only for Emacs 30.

* src/treesit.c (Ftreesit_parser_create): Use the buffer that's
given to treesit-parser-create, even if it's an indirect buffer.
---

diff --git a/src/treesit.c b/src/treesit.c
index f234698defd..3a0e9674f65 100644
--- a/src/treesit.c
+++ b/src/treesit.c
@@ -1560,6 +1560,9 @@ an indirect buffer.  */)
       CHECK_BUFFER (buffer);
       buf = XBUFFER (buffer);
     }
+
+  struct buffer *buffer_given = buf;
+
   if (buf->base_buffer)
     buf = buf->base_buffer;
 
@@ -1595,7 +1598,7 @@ an indirect buffer.  */)
 
   /* Create parser.  */
   Lisp_Object lisp_buf;
-  XSETBUFFER (lisp_buf, buf);
+  XSETBUFFER (lisp_buf, buffer_given);
   Lisp_Object lisp_parser = make_treesit_parser (lisp_buf,
 						 parser, NULL,
 						 language, tag);