8bf387183308af2ccd05188c723db5e5ee984e37
braney
  Wed Apr 30 15:52:15 2014 -0700
fix bug where multiWigs crashed with only zero or one subtracks turnedon

diff --git src/hg/hgTracks/multiWig.c src/hg/hgTracks/multiWig.c
index f2346cc..e3e7966 100644
--- src/hg/hgTracks/multiWig.c
+++ src/hg/hgTracks/multiWig.c
@@ -311,30 +311,33 @@
     }
 slReverse(&refList);
 minMaxVals(refList, &minVal, &maxVal, wigCart->windowingFunction,  wigCart->alwaysZero, wgo->yOffsets);
 slFreeList(&refList);
 
 if (!wigCart->autoScale)
     {
     minVal = wigCart->minY;
     maxVal = wigCart->maxY;
     }
 
 /* Loop through again setting up the wigCarts of the children to have minY/maxY for
  * our limits and autoScale off. */
 for (subtrack = tg->subtracks; subtrack != NULL; subtrack = subtrack->next)
     {
+    if (!isSubtrackVisible(subtrack))
+	continue;
+
     struct wigCartOptions *wigCart = subtrack->extraUiData;
     wigCart->minY = minVal;
     wigCart->maxY = maxVal;
     wigCart->autoScale = wiggleScaleManual;
     struct preDrawContainer *pre = subtrack->preDrawContainer;
     pre->graphUpperLimit = maxVal;
     pre->graphLowerLimit = minVal;
     
     }
 
 int numTrack = 0;
 for (subtrack = tg->subtracks; subtrack != NULL; subtrack = subtrack->next)
     {
     if (isSubtrackVisible(subtrack))
 	{