Bug 89824 [Forms] Position of Go button in Help Search view changes
If you expand and contract the Default Scope area the position of the Go button will shift (and the combo will shrink and grow). I will attach two screencaps - note the space to the right of the Go button.
bundles/org.eclipse.ui.forms/src/org/eclipse/ui/forms/widgets/TableWrapLayout.java
}
	void createGrid(Composite composite) {
		int row, column, rowFill, columnFill;
		Control[] children;
		TableWrapData spacerSpec;
		Vector growingCols = new Vector();
		Vector growingRows = new Vector();
		rowspans = new Hashtable();
		 
		children = composite.getChildren();
		if (children.length == 0)
			return;
		 
		grid.addElement(createEmptyRow());
		row = 0;
		column = 0;
		
		
		
		for (int i = 0; i < children.length; i++) {
			
			Control child = children[i];
			TableWrapData spec = (TableWrapData) child.getLayoutData();
			while (((TableWrapData[]) grid.elementAt(row))[column] != null) {
				column = column + 1;
				if (column >= numColumns) {
					row = row + 1;
					column = 0;
					if (row >= grid.size()) {
						grid.addElement(createEmptyRow());