NPE on 'Find next' after creating new view

**obscure**

Import a PDB file (3WV) and make sure that both temperature factor and secondary structure annotation are shown.

Open the find window and put in a simple regex (e.g. 'st+'). Hit find a few times.

Click in the alignment frame and create a new view. Don't adjust the window size - the annotation panel height is incorrectly set so that no sequences are visible.

Now hit the 'Find' button again - NPEs appear on the console:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at jalview.gui.SeqCanvas.drawMappedPositions(SeqCanvas.java:1484)
at jalview.gui.SeqCanvas.highlightSearchResults(SeqCanvas.java:1375)
at jalview.gui.AlignmentPanel.highlightSearchResults(AlignmentPanel.java:346)
at jalview.gui.Finder.doSearch(Finder.java:303)
at jalview.gui.Finder.findNext_actionPerformed(Finder.java:147)
at jalview.jbgui.GFinder$2.actionPerformed(GFinder.java:118)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6535)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)