patch 9.1.2096: Vim9: truthiness issue with objects

Problem:  Vim9: truthiness issue with objects
          (kennypete)
Solution: Return true for an non-null object
          (Yegappan Lakshmanan)

related: #19173
closes:  #19213

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

runtime/doc/vim9.txt

@@ -1,4 +1,4 @@
-*vim9.txt*	For Vim version 9.1.  Last change: 2025 Dec 03
+*vim9.txt*	For Vim version 9.1.  Last change: 2026 Jan 19
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -1084,8 +1084,11 @@ empty list and dict is falsy:
 	special		true or v:true
 	job		when not NULL
 	channel		when not NULL
-	class		when not NULL
-	object		when not NULL (TODO: when isTrue() returns true)
+	class		not applicable
+	object		when not NULL
+	enum		not applicable
+	enum value	always
+	typealias	not applicable
 
 The boolean operators "||" and "&&" expect the values to be boolean, zero or
 one: >

src/testdir/test_vim9_expr.vim

@@ -231,6 +231,38 @@ def Test_expr1_falsy()
   END
   v9.CheckDefAndScriptSuccess(lines)
 
+  # falsy operator with objects and enum values
+  lines =<< trim END
+    vim9script
+    class C
+    endclass
+
+    var c = C.new()
+    assert_equal(c, c ?? 'falsy')
+    assert_equal('truthy', !c ?? 'truthy')
+    assert_equal('falsy', null_object ?? 'falsy')
+    assert_equal(true, !null_object ?? 'truthy')
+
+    enum Color
+      Red,
+      Blue
+    endenum
+    assert_equal(Color.Red, Color.Red ?? 'falsy')
+    assert_equal('truthy', !Color.Red ?? 'truthy')
+
+    def Fn()
+      var c2 = C.new()
+      assert_equal(c2, c2 ?? 'falsy')
+      assert_equal('truthy', !c2 ?? 'truthy')
+      assert_equal('falsy', null_object ?? 'falsy')
+      assert_equal(true, !null_object ?? 'truthy')
+      assert_equal(Color.Red, Color.Red ?? 'falsy')
+      assert_equal('truthy', !Color.Red ?? 'truthy')
+    enddef
+    Fn()
+  END
+  v9.CheckSourceScriptSuccess(lines)
+
   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)

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2096,
 /**/
     2095,
 /**/

src/vim9execute.c

@@ -8127,12 +8127,15 @@ tv2bool(typval_T *tv)
 #endif
 	case VAR_BLOB:
 	    return tv->vval.v_blob != NULL && tv->vval.v_blob->bv_ga.ga_len > 0;
+
+	case VAR_OBJECT:
+	    return tv->vval.v_object != NULL;
+
 	case VAR_UNKNOWN:
 	case VAR_ANY:
 	case VAR_VOID:
 	case VAR_INSTR:
 	case VAR_CLASS:
-	case VAR_OBJECT:
 	case VAR_TYPEALIAS:
 	    break;
     }