patch 9.1.1812: completion: flicker with slow LSPs
Commit:
https://github.com/vim/vim/commit/71b97f29054135151d618433a11ce611ba25844d
Author: Girish Palya <[email protected]>
Date: Mon Sep 29 20:56:06 2025 +0000
patch 9.1.1812: completion: flicker with slow LSPs
Problem: completion: flicker with slow LSPs
Solution: Disable flushing the changed text (Girish Palya).
In insert-mode completion, the leader text is temporarily deleted while
searching for completion candidates. If the LSP server responds slowly,
the client may call `:sleep` to wait, which triggers `out_flush()`. This
causes the deleted text to briefly disappear before being redrawn when
results arrive, producing a visible flicker.
There are two possible fixes:
1. Suppress flushing while a user function (e.g. LSP client) is waiting.
2. Reinsert the deleted text before invoking the user function.
This Commit implements (1), which is the simpler solution, though somewhat
heavy-handed. If you think this may introduce unwanted side effects, I
can rework it to use (2).
closes: #18439
Signed-off-by: Girish Palya <[email protected]>
Signed-off-by: Christian Brabandt <[email protected]>
diff --git a/src/globals.h b/src/globals.h
index 5e2f7b0f4..b105ce515 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -1133,6 +1133,9 @@ EXTERN int secure INIT(= FALSE);
// allowed, e.g. when sourcing .exrc or .vimrc
// in current directory
+EXTERN int no_flush INIT(= 0);
+ // non-zero to prevent flushing output buffer
+
EXTERN int textlock INIT(= 0);
// non-zero when changing text and jumping to
// another window or editing another buffer is
diff --git a/src/insexpand.c b/src/insexpand.c
index 286fc0b47..17d0965ff 100644
--- a/src/insexpand.c
+++ b/src/insexpand.c
@@ -3601,8 +3601,18 @@ expand_by_function(int type, char_u *base, callback_T
*cb)
// Insert mode in another buffer.
++textlock;
+ // Suppress flushing of the output buffer. Without this, text removed
+ // temporarily by ins_compl_delete() is flushed to the terminal and shown
+ // as deleted, only to be redrawn later. This causes visible flicker (typed
+ // chars disappear and reappear) when a user func (e.g. an LSP server)
+ // responds slowly. Such funcs may call sleep(), which indirectly triggers
+ // out_flush(). We want deleted text to remain visible.
+ ++no_flush;
+
retval = call_callback(cb, 0, &rettv, 2, args);
+ --no_flush;
+
// Call a function, which returns a list or dict.
if (retval == OK)
{
@@ -6093,7 +6103,6 @@ find_next_completion_match(
int compl_fuzzy_match = (cur_cot_flags & COT_FUZZY) != 0;
string_T *leader;
-
while (--todo >= 0)
{
if (compl_shows_dir_forward() && compl_shown_match->cp_next != NULL)
@@ -6203,7 +6212,7 @@ find_next_completion_match(
*
* Note that this function may be called recursively once only. First with
* "allow_get_expansion" TRUE, which calls ins_compl_get_exp(), which in turn
- * calls this function with "allow_get_expansion" FALSE.
+ * calls this with "allow_get_expansion" FALSE (via ins_compl_check_keys()).
*/
static int
ins_compl_next(
diff --git a/src/term.c b/src/term.c
index e23085837..0fa5652b3 100644
--- a/src/term.c
+++ b/src/term.c
@@ -2772,7 +2772,7 @@ out_flush(void)
{
int len;
- if (out_pos == 0)
+ if (no_flush > 0 || out_pos == 0)
return;
// set out_pos to 0 before ui_write, to avoid recursiveness
diff --git a/src/testdir/test_ins_complete.vim
b/src/testdir/test_ins_complete.vim
index e7346b8b5..5f5fb8d97 100644
--- a/src/testdir/test_ins_complete.vim
+++ b/src/testdir/test_ins_complete.vim
@@ -420,7 +420,7 @@ func Test_CompleteDoneDict()
au CompleteDone * :call <SID>CompleteDone_CheckCompletedItemDict(0)
set complete=.,F<SID>CompleteDone_CompleteFuncDict
- execute "normal a\<C-N>\<C-Y>"
+ execute "normal dda\<C-N>\<C-Y>"
set complete&
call assert_equal(['one', 'two'], v:completed_item[ 'user_data' ])
@@ -473,7 +473,7 @@ func Test_CompleteDoneDictNoUserData()
let s:called_completedone = 0
set complete=.,F<SID>CompleteDone_CompleteFuncDictNoUserData
- execute "normal a\<C-N>\<C-Y>"
+ execute "normal dda\<C-N>\<C-Y>"
set complete&
call assert_equal('', v:completed_item[ 'user_data' ])
diff --git a/src/version.c b/src/version.c
index 5c74bc0e1..d989f097a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -729,6 +729,8 @@ static char *(features[]) =
static int included_patches[] =
{ /* Add new patch number below this line */
+/**/
+ 1812,
/**/
1811,
/**/
--
--
You received this message from the "vim_dev" maillist.
Do not top-post! Type your reply below the text you are replying to.
For more information, visit http://www.vim.org/maillist.php
---
You received this message because you are subscribed to the Google Groups
"vim_dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion visit
https://groups.google.com/d/msgid/vim_dev/E1v3Kya-001sqb-5z%40256bit.org.
