Merge pull request gui-cs#3353 from BDisp/v2_tabindex-fix_3351

Fixes gui-cs#3351. TabIndex with the same setter value but with wrong index return without set the correct value.

Terminal.Gui/View/ViewKeyboard.cs

@@ -267,7 +267,7 @@ public int TabIndex
                 return;
             }
 
-            if (_tabIndex == value)
+            if (_tabIndex == value && TabIndexes.IndexOf (this) == value)
             {
                 return;
             }

UnitTests/View/NavigationTests.cs

@@ -1290,6 +1290,79 @@ public void TabIndex_Set_CanFocus_ValidValues ()
         r.Dispose ();
     }
 
+    [Fact]
+    public void TabIndex_Invert_Order ()
+    {
+        var r = new View ();
+        var v1 = new View () { Id = "1", CanFocus = true };
+        var v2 = new View () { Id = "2", CanFocus = true };
+        var v3 = new View () { Id = "3", CanFocus = true };
+
+        r.Add (v1, v2, v3);
+
+        v1.TabIndex = 2;
+        v2.TabIndex = 1;
+        v3.TabIndex = 0;
+        Assert.True (r.TabIndexes.IndexOf (v1) == 2);
+        Assert.True (r.TabIndexes.IndexOf (v2) == 1);
+        Assert.True (r.TabIndexes.IndexOf (v3) == 0);
+
+        Assert.True (r.Subviews.IndexOf (v1) == 0);
+        Assert.True (r.Subviews.IndexOf (v2) == 1);
+        Assert.True (r.Subviews.IndexOf (v3) == 2);
+    }
+
+    [Fact]
+    public void TabIndex_Invert_Order_Added_One_By_One_Does_Not_Do_What_Is_Expected ()
+    {
+        var r = new View ();
+        var v1 = new View () { Id = "1", CanFocus = true };
+        r.Add (v1);
+        v1.TabIndex = 2;
+        var v2 = new View () { Id = "2", CanFocus = true };
+        r.Add (v2);
+        v2.TabIndex = 1;
+        var v3 = new View () { Id = "3", CanFocus = true };
+        r.Add (v3);
+        v3.TabIndex = 0;
+
+        Assert.False (r.TabIndexes.IndexOf (v1) == 2);
+        Assert.True (r.TabIndexes.IndexOf (v1) == 1);
+        Assert.False (r.TabIndexes.IndexOf (v2) == 1);
+        Assert.True (r.TabIndexes.IndexOf (v2) == 2);
+        // Only the last is in the expected index
+        Assert.True (r.TabIndexes.IndexOf (v3) == 0);
+
+        Assert.True (r.Subviews.IndexOf (v1) == 0);
+        Assert.True (r.Subviews.IndexOf (v2) == 1);
+        Assert.True (r.Subviews.IndexOf (v3) == 2);
+    }
+
+    [Fact]
+    public void TabIndex_Invert_Order_Mixed ()
+    {
+        var r = new View ();
+        var vl1 = new View () { Id = "vl1" };
+        var v1 = new View () { Id = "v1", CanFocus = true };
+        var vl2 = new View () { Id = "vl2" };
+        var v2 = new View () { Id = "v2", CanFocus = true };
+        var vl3 = new View () { Id = "vl3" };
+        var v3 = new View () { Id = "v3", CanFocus = true };
+
+        r.Add (vl1, v1, vl2, v2, vl3, v3);
+
+        v1.TabIndex = 2;
+        v2.TabIndex = 1;
+        v3.TabIndex = 0;
+        Assert.True (r.TabIndexes.IndexOf (v1) == 4);
+        Assert.True (r.TabIndexes.IndexOf (v2) == 2);
+        Assert.True (r.TabIndexes.IndexOf (v3) == 0);
+
+        Assert.True (r.Subviews.IndexOf (v1) == 1);
+        Assert.True (r.Subviews.IndexOf (v2) == 3);
+        Assert.True (r.Subviews.IndexOf (v3) == 5);
+    }
+
     [Fact]
     public void TabStop_All_False_And_All_True_And_Changing_TabStop_Later ()
     {