patch 9.1.0197: Vim9: problem evaluating negated boolean logic

Problem:  Vim9: problem evaluating negated boolean logic
          (lxhillwind)
Solution: Don't clear the first value on short circuit evaluation
          (Yegappan Lakshmanan)

fixes: #14265
closes: #14269

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
index 6285ba1..7764b37 100644
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -311,6 +311,33 @@
       assert_equal([1], g:vals)
   END
   v9.CheckDefAndScriptSuccess(lines)
+
+  # test the short-circuit operation
+  lines =<< trim END
+    assert_equal(true, true && true)
+    assert_equal(false, true && !true)
+    assert_equal(false, !true && true)
+    assert_equal(false, !true && !true)
+
+    assert_equal(true, true || true)
+    assert_equal(true, true || !true)
+    assert_equal(true, !true || true)
+    assert_equal(false, !true || !true)
+
+    assert_equal(false, false && false)
+    assert_equal(false, false && !false)
+    assert_equal(false, !false && false)
+    assert_equal(true, !false && !false)
+
+    assert_equal(false, false || false)
+    assert_equal(true, false || !false)
+    assert_equal(true, !false || false)
+    assert_equal(true, !false || !false)
+
+    assert_equal(false, !true && !true && !true)
+    assert_equal(true, !false || !false || !false)
+  END
+  v9.CheckDefAndScriptSuccess(lines)
 enddef
 
 def Test_expr2_vimscript()