CTabFolder Overlap between top right control and toolbar

[jonahgraham]

org.eclipse.swt.tests.junit.Test_org_eclipse_swt_custom_CTabFolder.test_childControlOverlap() fails semi-randomly because depending on window size it can cause the top right control and toolbar to be overlapping, such as in this screenshot:

[jonahgraham]

I accidentally ran into this while working on #2768 because the changes I made happened to use different sizes of screens or something else that caused problems.

It turns out that the bug is not GTK specific and affects all platforms - this can be seen by resizing the window in the tests:

diff --git a/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_custom_CTabFolder.java b/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_custom_CTabFolder.java
index 8b1b6e2166..de68223fdb 100644
--- a/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_custom_CTabFolder.java	
+++ b/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_custom_CTabFolder.java	
@@ -368,6 +368,17 @@ public void test_childControlOverlap() {
 		}
 		processEvents();
 		checkElementOverlap(ctabFolder);
+
+		int x = shell.getSize().x;
+		int y = shell.getSize().y;
+		for (int i = 200; i < 500; i++) {
+			shell.setSize(i, y);
+			processEvents();
+			checkElementOverlap(ctabFolder);
+		}
+		shell.setSize(x, y);
+		processEvents();
+		checkElementOverlap(ctabFolder);
 	};
 
 	makeCleanEnvironment(SWT.CLOSE);

This issue is probably the same as Bug 384851 (wayback in case you also get a 500 error).