patch 8.2.3597: Vim seems to hang when writing a long text to a terminalv8.2.3597

Problem:    Vim seems to hang when writing a very long text to a terminal
            window.
Solution:   Limit the amount of text based on 'termwinscroll'. (issue #9080)

1 files changed, 15 insertions, 1 deletions

diff --git a/src/terminal.c b/src/terminal.c
index 1adf690ad..fb8b2881f 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -1130,10 +1130,24 @@ get_tty_part(term_T *term UNUSED)
  * Write job output "msg[len]" to the vterm.
  */
     static void
-term_write_job_output(term_T *term, char_u *msg, size_t len)
+term_write_job_output(term_T *term, char_u *msg_arg, size_t len_arg)
 {
+    char_u	*msg = msg_arg;
+    size_t	len = len_arg;
     VTerm	*vterm = term->tl_vterm;
     size_t	prevlen = vterm_output_get_buffer_current(vterm);
+    size_t	limit = term->tl_buffer->b_p_twsl * term->tl_cols * 3;
+
+    // Limit the length to 'termwinscroll' * cols * 3 bytes.  Keep the text at
+    // the end.
+    if (len > limit)
+    {
+	char_u *p = msg + len - limit;
+
+	p -= (*mb_head_off)(msg, p);
+	len -= p - msg;
+	msg = p;
+    }
 
     vterm_input_write(vterm, (char *)msg, len);