Commit: patch 9.2.0768: legacy/vim9cmd modifiers are not exclusive

[Christian Brabandt]

patch 9.2.0768: legacy/vim9cmd modifiers are not exclusive

Commit: https://github.com/vim/vim/commit/a9b46d323b16673d6b26360ef7907afb1b19cd0f
Author: Illia Bobyr <illia...@gmail.com>
Date: Thu Jul 2 18:51:04 2026 +0000

patch 9.2.0768: legacy/vim9cmd modifiers are not exclusive

Problem: legacy/vim9cmd modifiers are not exclusive
Solution: when parsing command modifiers clear the other flag
(Illia Bobyr)

When one of the ":legacy" or ":vim9cmd" prefixes is used, it sets a
flag. As the rest of the code might check either of the flags, setting
both could produce confusing results. It does not make a lot of sense
to use both prefixes in the same command. But just in case it is used,
selecting the last prefix seems reasonable.

closes: #20682

Signed-off-by: Illia Bobyr <illia...@gmail.com>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index e716613ec..55db2d8d4 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -3092,6 +3092,9 @@ parse_command_modifiers(
_(e_legacy_must_be_followed_by_command);
return FAIL;
}
+ // Make sure we do not have both legacy and Vim9
+ // flags set at the same time.
+ cmod->cmod_flags &= ~CMOD_VIM9CMD;
cmod->cmod_flags |= CMOD_LEGACY;
continue;
}
@@ -3177,6 +3180,9 @@ parse_command_modifiers(
_(e_vim9cmd_must_be_followed_by_command);
return FAIL;
}
+ // Make sure we do not have both legacy and Vim9
+ // flags set at the same time.
+ cmod->cmod_flags &= ~CMOD_LEGACY;
cmod->cmod_flags |= CMOD_VIM9CMD;
continue;
}
diff --git a/src/testdir/test_vim9_cmd.vim b/src/testdir/test_vim9_cmd.vim
index 1f421e2a4..8eaa2a875 100644
--- a/src/testdir/test_vim9_cmd.vim
+++ b/src/testdir/test_vim9_cmd.vim
@@ -134,6 +134,23 @@ def Test_legacy_vim9cmd_preserved_by_options()
v9.CheckScriptSuccess(lines)
enddef

+def Test_legacy_vim9cmd_exclusive()
+ # Make sure that only one of the "legacy" or "vim9cmd" prefixes is applied.
+
+ # Invalid as vim9syntax.
+ call assert_fails("legacy vim9cmd echo 'a' . 'b'", 'E15:')
+ call assert_fails("legacy vim9cmd legacy vim9cmd echo 'a' . 'b'", 'E15:')
+
+ # Invalid legacy syntax.
+ call assert_fails("vim9cmd legacy echo (x) => x", 'E121:')
+ call assert_fails("vim9cmd legacy vim9cmd legacy echo (x) => x", 'E121:')
+
+ # Validate legacy/vim9 syntax being used.
+ call assert_equal('ab', trim(execute("vim9cmd legacy echo 'a' . 'b'")))
+ call assert_equal('true',
+ execute('legacy vim9cmd echo type((x) => x) == v:t_func')->trim())
+enddef
+
def Test_defcompile_fails()
assert_fails('defcompile NotExists', 'E1061:')
assert_fails('defcompile debug debug Test_defcompile_fails', 'E488:')
diff --git a/src/version.c b/src/version.c
index da6de9304..d9a2c3310 100644
--- a/src/version.c
+++ b/src/version.c
@@ -759,6 +759,8 @@ static char *(features[]) =

static int included_patches[] =
{ /* Add new patch number below this line */
+/**/
+ 768,
/**/
767,
/**/