emacs-30 bf23382f1f2 4/4: Read more on each call to treesit's buffer reader

[Yuan Fu]

branch: emacs-30
commit bf23382f1f2d6ea072db4e4750f8a345f77a3ef2
Author: Yuan Fu <casouri@gmail.com>
Commit: Yuan Fu <casouri@gmail.com>

    Read more on each call to treesit's buffer reader
    
    * src/treesit.c (treesit_read_buffer): Read until the gap or visible
    end, instead of reading a single char.
---
 src/treesit.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/treesit.c b/src/treesit.c
index 970754f3c1b..b047f0344cc 100644
--- a/src/treesit.c
+++ b/src/treesit.c
@@ -1225,11 +1225,13 @@ treesit_read_buffer (void *parser, uint32_t byte_index,
       beg = NULL;
       len = 0;
     }
-  /* Normal case, read a character.  */
+  /* Normal case, read until the gap or visible end.  */
   else
     {
       beg = (char *) BUF_BYTE_ADDRESS (buffer, byte_pos);
-      len = BYTES_BY_CHAR_HEAD ((int) *beg);
+      ptrdiff_t gap_bytepos = buffer->text->gpt_byte;
+      len = (byte_pos < gap_bytepos)
+           ? gap_bytepos - byte_pos : visible_end - byte_pos;
     }
   /* We never let tree-sitter to parse buffers that large so this
      assertion should never hit.  */