Bug 177405 [Preferences] Layout issues with Text Boxes and Scrollbars
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
vdiff = Math.max(0, vdiff);
					setShellSize(shellSize.x + hdiff, shellSize.y + vdiff);
					lastShellSize = shell.getSize();
					if (currentPage.getControl().getSize().x == 0) {
						currentPage.getControl().setSize(containerSize);
					}
				
			} else {
				currentPage.setSize(containerSize);
			}
		}
		
		scrolled.setMinSize(contentSize);
		
		
		
		Control[] children = pageContainer.getChildren();
		Control currentControl = currentPage.getControl();
		for (int i = 0; i < children.length; i++) {
			if (children[i] != currentControl) {
				children[i].setVisible(false);
			}
		}
		
		currentPage.setVisible(true);
		if (oldPage != null) {
			oldPage.setVisible(false);
		}
		
		update();