Merge pull request #2827 from MahApps/develop

Merging content for 1.4.2 develop to master

Author: punker76

docs/release-notes/1.4.2.md

@@ -20,3 +20,4 @@
 - [#2770](https://github.com/MahApps/MahApps.Metro/issues/2770) Increase Win10 ToggleSwitch Default Margins
 - [#2780](https://github.com/MahApps/MahApps.Metro/issues/2780) External Dialogs not visible with MainWindow set to IgnoreTaskbarOnMaximize
 - [#2748](https://github.com/MahApps/MahApps.Metro/issues/2748) Access Denied
+- [#2591](https://github.com/MahApps/MahApps.Metro/issues/2591) Weird MetroProgressBar animation with IsIndeterminate=true

src/MahApps.Metro/MahApps.Metro.Shared/Controls/MetroProgressBar.cs

@@ -112,6 +112,7 @@ private double ActualSize(bool invalidateMeasureArrange)
         {
             if (invalidateMeasureArrange)
             {
+                this.UpdateLayout();
                 this.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));
                 this.InvalidateArrange();
             }