Merge branch 'bug/JAL-2491' into develop

diff --cc src/jalview/appletgui/SeqPanel.java
index 2d2e3fd,f5955d1..14ea222
--- 1/src/jalview/appletgui/SeqPanel.java
--- 2/src/jalview/appletgui/SeqPanel.java
+++ b/src/jalview/appletgui/SeqPanel.java
@@@ -236,11 -235,11 +236,11 @@@ public class SeqPanel extends Panel imp
        HiddenColumns hidden = av.getAlignment().getHiddenColumns();
        while (seqCanvas.cursorY < ranges.getStartSeq())
        {
-         ap.scrollUp(true);
+         ranges.scrollUp(true);
        }
 -      while (seqCanvas.cursorY + 1 > ranges.getEndSeq())
 +      while (seqCanvas.cursorY > ranges.getEndSeq())
        {
-         ap.scrollUp(false);
+         ranges.scrollUp(false);
        }
        while (seqCanvas.cursorX < hidden.adjustForHiddenColumns(ranges
                .getStartRes()))

diff --cc src/jalview/gui/SeqPanel.java
Simple merge