Commit: patch 9.1.0808: Terminal scrollback doesn't shrink when decreasing 'termwinscroll'

[Christian Brabandt]

patch 9.1.0808: Terminal scrollback doesn't shrink when decreasing 'termwinscroll'

Commit: https://github.com/vim/vim/commit/6d5f4a0bed7644d5fcd442000a902ed3ae0704fe
Author: Milly <mill...@gmail.com>
Date: Tue Oct 22 23:17:45 2024 +0200

patch 9.1.0808: Terminal scrollback doesn't shrink when decreasing 'termwinscroll'

Problem: Terminal scrollback doesn't shrink when reducing
'termwinscroll'
Solution: Check if option value was decreased (Milly).

closes: #15904

Signed-off-by: Milly <mill...@gmail.com>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/src/option.c b/src/option.c
index 179c61ea3..84c469ea6 100644
--- a/src/option.c
+++ b/src/option.c
@@ -4259,6 +4259,26 @@ did_set_termguicolors(optset_T *args UNUSED)
}
#endif

+#if defined(FEAT_TERMINAL) || defined(PROTO)
+/*
+ * Process the updated 'termwinscroll' option value.
+ */
+ char *
+did_set_termwinscroll(optset_T *args)
+{
+ long *pp = (long *)args->os_varp;
+ char *errmsg = NULL;
+
+ if (*pp < 1)
+ {
+ errmsg = e_argument_must_be_positive;
+ *pp = 1;
+ }
+
+ return errmsg;
+}
+#endif
+
/*
* Process the updated 'terse' option value.
*/
diff --git a/src/optiondefs.h b/src/optiondefs.h
index 42e62e7d2..ccc527e08 100644
--- a/src/optiondefs.h
+++ b/src/optiondefs.h
@@ -2563,7 +2563,7 @@ static struct vimoption options[] =
SCTX_INIT},
{"termwinscroll", "twsl", P_NUM|P_VI_DEF|P_VIM|P_RBUF,
#ifdef FEAT_TERMINAL
- (char_u *)&p_twsl, PV_TWSL, NULL, NULL,
+ (char_u *)&p_twsl, PV_TWSL, did_set_termwinscroll, NULL,
{(char_u *)10000L, (char_u *)10000L}
#else
(char_u *)NULL, PV_NONE, NULL, NULL,
diff --git a/src/proto/option.pro b/src/proto/option.pro
index 1659131a3..db92bf253 100644
--- a/src/proto/option.pro
+++ b/src/proto/option.pro
@@ -71,6 +71,7 @@ char *did_set_spell(optset_T *args);
char *did_set_swapfile(optset_T *args);
char *did_set_tabclose(optset_T *args);
char *did_set_termguicolors(optset_T *args);
+char *did_set_termwinscroll(optset_T *args);
char *did_set_terse(optset_T *args);
char *did_set_textauto(optset_T *args);
char *did_set_textmode(optset_T *args);
diff --git a/src/terminal.c b/src/terminal.c
index f61a54f7f..6edc21a11 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -3436,7 +3436,8 @@ limit_scrollback(term_T *term, garray_T *gap, int update_buffer)
if (gap->ga_len < term->tl_buffer->b_p_twsl)
return;

- int todo = term->tl_buffer->b_p_twsl / 10;
+ int todo = MAX(term->tl_buffer->b_p_twsl / 10,
+ gap->ga_len - term->tl_buffer->b_p_twsl);
int i;

curbuf = term->tl_buffer;
diff --git a/src/testdir/gen_opt_test.vim b/src/testdir/gen_opt_test.vim
index 1c231f9c5..34fffeff6 100644
--- a/src/testdir/gen_opt_test.vim
+++ b/src/testdir/gen_opt_test.vim
@@ -103,6 +103,7 @@ let test_values = {
\ 'sidescroll': [[0, 1, 8, 999], [-1]],
\ 'sidescrolloff': [[0, 1, 8, 999], [-1]],
\ 'tabstop': [[1, 4, 8, 12, 9999], [-1, 0, 10000]],
+ \ 'termwinscroll': [[1, 100, 99999], [-1, 0]],
\ 'textwidth': [[0, 1, 8, 99], [-1]],
\ 'timeoutlen': [[0, 8, 99999], [-1]],
\ 'titlelen': [[0, 1, 8, 9999], [-1]],
diff --git a/src/testdir/test_options.vim b/src/testdir/test_options.vim
index cbc84a471..73e6d850c 100644
--- a/src/testdir/test_options.vim
+++ b/src/testdir/test_options.vim
@@ -752,6 +752,9 @@ func Test_set_option_errors()
call assert_fails('set tabstop=10000', 'E474:')
call assert_fails('let &tabstop = 10000', 'E474:')
call assert_fails('set tabstop=5500000000', 'E474:')
+ if has('terminal')
+ call assert_fails('set termwinscroll=-1', 'E487:')
+ endif
call assert_fails('set textwidth=-1', 'E487:')
call assert_fails('set timeoutlen=-1', 'E487:')
call assert_fails('set updatecount=-1', 'E487:')
diff --git a/src/testdir/test_terminal.vim b/src/testdir/test_terminal.vim
index fa644d335..5343efb95 100644
--- a/src/testdir/test_terminal.vim
+++ b/src/testdir/test_terminal.vim
@@ -501,6 +501,21 @@ func Test_terminal_scrollback()
let lines = line('$')
call assert_inrange(91, 100, lines)

+ " When 'termwinscroll' becomes small, the scrollback should become small.
+ set termwinscroll=20
+ call term_sendkeys(buf, "echo set20\<CR>")
+ call WaitForAssert({-> assert_true([term_getline(buf, rows - 1), term_getline(buf, rows - 2)]->index('set20') >= 0)})
+ let lines = line('$')
+ call assert_inrange(19, 20, lines)
+
+ " When 'termwinscroll' under 10 which means 10% of it will be 0,
+ " the scrollback should become small.
+ set termwinscroll=1
+ call term_sendkeys(buf, "echo set1\<CR>")
+ call WaitForAssert({-> assert_true([term_getline(buf, rows - 1), term_getline(buf, rows - 2)]->index('set1') >= 0)})
+ let lines = line('$')
+ call assert_inrange(1, 2, lines)
+
call StopShellInTerminal(buf)
exe buf . 'bwipe'
set termwinscroll&
diff --git a/src/version.c b/src/version.c
index 2a85be943..5b4a85307 100644
--- a/src/version.c
+++ b/src/version.c
@@ -704,6 +704,8 @@ static char *(features[]) =

static int included_patches[] =
{ /* Add new patch number below this line */
+/**/
+ 808,
/**/
807,
/**/