Commit: patch 9.1.2101: Vim9: more truthiness issues

[Christian Brabandt]

patch 9.1.2101: Vim9: more truthiness issues

Commit: https://github.com/vim/vim/commit/a7d195415b31ca6168501cac3506e65beb484ada
Author: Yegappan Lakshmanan <yega...@yahoo.com>
Date: Tue Jan 20 19:46:33 2026 +0000

patch 9.1.2101: Vim9: more truthiness issues

Problem: Vim9: more truthiness issues
(kennypete)
Solution: Class, enum and typealias cannot be used with the falsy
operator (Yegappan Lakshmanan)

related: #19213
fixes: #19173
closes: #19216

Signed-off-by: Yegappan Lakshmanan <yega...@yahoo.com>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
index 87b821638..b66372884 100644
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -263,6 +263,67 @@ def Test_expr1_falsy()
END
v9.CheckSourceScriptSuccess(lines)

+ # class cannot be used with the falsy operator
+ lines =<< trim END
+ vim9script
+ class A
+ endclass
+ echo A ?? 'falsy'
+ END
+ v9.CheckSourceScriptFailure(lines, 'E1405: Class "A" cannot be used as a value')
+
+ lines =<< trim END
+ vim9script
+ class B
+ endclass
+ echo !B
+ END
+ v9.CheckSourceScriptFailure(lines, 'E1405: Class "B" cannot be used as a value')
+
+ lines =<< trim END
+ vim9script
+ echo null_class ?? 'falsy'
+ END
+ v9.CheckSourceScriptFailure(lines, 'E1405: Class "" cannot be used as a value')
+
+ lines =<< trim END
+ vim9script
+ echo !null_class
+ END
+ v9.CheckSourceScriptFailure(lines, 'E1405: Class "" cannot be used as a value')
+
+ # enum cannot be used with the falsy operator
+ lines =<< trim END
+ vim9script
+ enum E1
+ endenum
+ echo E1 ?? 'falsy'
+ END
+ v9.CheckSourceScriptFailure(lines, 'E1421: Enum "E1" cannot be used as a value')
+
+ lines =<< trim END
+ vim9script
+ enum E2
+ endenum
+ echo !E2
+ END
+ v9.CheckSourceScriptFailure(lines, 'E1421: Enum "E2" cannot be used as a value')
+
+ # typealias cannot be used with the falsy operator
+ lines =<< trim END
+ vim9script
+ type T1 = list<bool>
+ echo T1 ?? 'falsy'
+ END
+ v9.CheckSourceScriptFailure(lines, 'E1403: Type alias "T1" cannot be used as a value')
+
+ lines =<< trim END
+ vim9script
+ type T2 = list<bool>
+ echo !T2
+ END
+ v9.CheckSourceScriptFailure(lines, 'E1403: Type alias "T2" cannot be used as a value')
+
var msg = "White space required before and after '??'"
call v9.CheckDefAndScriptFailure(["var x = 1?? 'one' : 'two'"], msg, 1)
call v9.CheckDefAndScriptFailure(["var x = 1 ??'one' : 'two'"], msg, 1)
diff --git a/src/version.c b/src/version.c
index 61720c936..d6644bf10 100644
--- a/src/version.c
+++ b/src/version.c
@@ -734,6 +734,8 @@ static char *(features[]) =

static int included_patches[] =
{ /* Add new patch number below this line */
+/**/
+ 2101,
/**/
2100,
/**/
diff --git a/src/vim9execute.c b/src/vim9execute.c
index 9763cd95b..bdea74f66 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -8131,12 +8131,15 @@ tv2bool(typval_T *tv)
case VAR_OBJECT:
return tv->vval.v_object != NULL;

+ case VAR_CLASS:
+ case VAR_TYPEALIAS:
+ check_typval_is_value(tv);
+ break;
+
case VAR_UNKNOWN:
case VAR_ANY:
case VAR_VOID:
case VAR_INSTR:
- case VAR_CLASS:
- case VAR_TYPEALIAS:
break;
}
return FALSE;