Commit: patch 9.1.1800: completion: strange behaviour with 'ac' completeopt=longest,preinsert

[Christian Brabandt]

patch 9.1.1800: completion: strange behaviour with 'ac' completeopt=longest,preinsert

Commit: https://github.com/vim/vim/commit/d35e5e4237ec578962d3d577bc5a4e4f6bf4abb2
Author: Girish Palya <giri...@gmail.com>
Date: Sun Sep 28 17:12:55 2025 +0000

patch 9.1.1800: completion: strange behaviour with 'ac' completeopt=longest,preinsert

Problem: completion: strange behaviour with 'ac'
completeopt=longest,preinsert (zeertzjq)
Solution: Let preinsert take precedence (Girish Palya)

fixes: #18410
closes: #18428

Signed-off-by: Girish Palya <giri...@gmail.com>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/src/insexpand.c b/src/insexpand.c
index 2aabacd83..35068cdae 100644
--- a/src/insexpand.c
+++ b/src/insexpand.c
@@ -3100,7 +3100,8 @@ ins_compl_prep(int c)
if (ctrl_x_mode_not_defined_yet()
|| (ctrl_x_mode_normal() && !compl_started))
{
- compl_get_longest = (get_cot_flags() & COT_LONGEST) != 0;
+ compl_get_longest = (get_cot_flags() & COT_LONGEST)
+ && !ins_compl_has_autocomplete();
compl_used_match = TRUE;
}

diff --git a/src/testdir/dumps/Test_autocompletedelay_7.dump b/src/testdir/dumps/Test_autocompletedelay_7.dump
index 08f4059c6..017156bd0 100644
--- a/src/testdir/dumps/Test_autocompletedelay_7.dump
+++ b/src/testdir/dumps/Test_autocompletedelay_7.dump
@@ -2,9 +2,9 @@
|f|o@1|b|a|r| @68
|f|o@1|b|a|r|b|a|z| @65
|f|o@1> @71
-|f+0#0000001#ffd7ff255|o@1| @11| +0#4040ff13#ffffff0@59
+|f+0#0000001#e0e0e08|o@1| @11| +0#4040ff13#ffffff0@59
|f+0#0000001#ffd7ff255|o@1|b|a|r| @8| +0#4040ff13#ffffff0@59
|f+0#0000001#ffd7ff255|o@1|b|a|r|b|a|z| @5| +0#4040ff13#ffffff0@59
|~| @73
|~| @73
-|-+2#0000000&@1| |K|e|y|w|o|r|d| |c|o|m|p|l|e|t|i|o|n| |(|^|N|^|P|)| |B+0#e000002&|a|c|k| |a|t| |o|r|i|g|i|n|a|l| +0#0000000&@29
+|-+2#0000000&@1| |K|e|y|w|o|r|d| |c|o|m|p|l|e|t|i|o|n| |(|^|N|^|P|)| |m+0#00e0003&|a|t|c|h| |1| |o|f| |3| +0#0000000&@33
diff --git a/src/testdir/test_ins_complete.vim b/src/testdir/test_ins_complete.vim
index 48623f26a..e6abe98e4 100644
--- a/src/testdir/test_ins_complete.vim
+++ b/src/testdir/test_ins_complete.vim
@@ -5721,7 +5721,7 @@ func Test_autocompletedelay()
call VerifyScreenDump(buf, 'Test_autocompletedelay_6', {})

" During delay wait, user can open menu using CTRL_N completion
- call term_sendkeys(buf, "\<Esc>:set completeopt=menuone,longest\<CR>")
+ call term_sendkeys(buf, "\<Esc>:set completeopt=menuone\<CR>")
call term_sendkeys(buf, "Sf\<C-N>")
call VerifyScreenDump(buf, 'Test_autocompletedelay_7', {})

@@ -5871,6 +5871,16 @@ func Test_autocomplete_longest()
call feedkeys("Go\<ESC>", 'tx')
call DoTest("f\<C-N>\<C-N>\<BS>\<BS>\<BS>\<BS>", 'foo', 3)

+ " Issue #18410: When both 'preinsert' and 'longest' are set, 'preinsert'
+ " takes precedence
+ %delete
+ set autocomplete completeopt+=longest,preinsert
+ call setline(1, ['foobar', 'foofoo', 'foobaz', ''])
+ call feedkeys("G", 'tx')
+ call DoTest("f", 'foobar', 2)
+ call assert_equal(1, g:preinserted)
+
+ " Undo
%delete _
let &l:undolevels = &l:undolevels
normal! ifoo
diff --git a/src/version.c b/src/version.c
index 5c1424ed3..1faf29ad3 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 */
+/**/
+ 1800,
/**/
1799,
/**/