09a54c525e1702d50b28a5635bdf736bf47cdf00
max
  Sun Jul 25 23:05:15 2021 -0700
fixing zoom keys again, refs #27892

diff --git src/hg/js/hgTracks.js src/hg/js/hgTracks.js
index 70de7d1..fb9b2d9 100644
--- src/hg/js/hgTracks.js
+++ src/hg/js/hgTracks.js
@@ -3389,32 +3389,33 @@
         position = genomePos.get().replace(/,/g,'');
     } else if (hgTracks.windows && hgTracks.nonVirtPosition) {
         position = hgTracks.nonVirtPosition;
     }
     var pos = parsePosition(position);
     if (pos) {
         var url = "hgc?hgsid="+getHgsid()+"&g=getDna&i=mixed&c="+pos.chrom+"&l="+pos.start+"&r="+pos.end+"&db="+getDb();
         window.location.href = url;
     }
     return false;
 }
 
 // A function for the keyboard shortcuts "zoom to x bp"
 function zoomTo(zoomSize) {
     var flankSize = Math.floor(zoomSize/2);
-    var pos = parsePosition(genomePos.get());
-    pos.replace("virt:", "multi:");
+    var posStr = genomePos.get();
+    posStr = posStr.replace("virt:", "multi:");
+    var pos = parsePosition(posStr);
     var mid = pos.start+(Math.floor((pos.end-pos.start)/2));
     var newStart = Math.max(mid - flankSize, 0);
     var newEnd = mid + flankSize - 1;
     var newPos = genomePos.setByCoordinates(pos.chrom, newStart, newEnd);
     if (hgTracks.virtualSingleChrom && (newPos.search("multi:")===0))
         newPos = genomePos.disguisePosition(newPosition); // DISGUISE?
     imageV2.navigateInPlace("position="+newPos, null, true);
 }
 
 // A function for the keyboard shortcuts "highlight add/clear/new"
 function highlightCurrentPosition(mode) {
     var pos = genomePos.get();
     if (mode=="new")
         dragSelect.highlightThisRegion(pos, false);
     else if (mode=="add")