62517dd2be5e6edf52dbeed10731fd95ed792baf
angie
  Mon Dec 12 08:39:06 2011 -0800
Feature #5019 (VCF support in track hubs): Pauline found that next/previtem arrows were appearing for VCF tracks in hubs, but they don't work.
Brian pointed out that the hgTracks handler can disable the inherited
settings that enable the arrows.  Done.  Not sure why the arrows appeared
only for hub VCF tracks, not VCF custom tracks.

diff --git src/hg/hgTracks/vcfTrack.c src/hg/hgTracks/vcfTrack.c
index 7ee68e0..7851f89 100644
--- src/hg/hgTracks/vcfTrack.c
+++ src/hg/hgTracks/vcfTrack.c
@@ -1120,30 +1120,34 @@
 errCatchEnd(errCatch);
 if (errCatch->gotError || vcff == NULL)
     {
     if (isNotEmpty(errCatch->message->string))
 	tg->networkErrMsg = cloneString(errCatch->message->string);
     tg->drawItems = bigDrawWarning;
     tg->totalHeight = bigWarnTotalHeight;
     }
 errCatchFree(&errCatch);
 }
 
 void vcfTabixMethods(struct track *track)
 /* Methods for VCF + tabix files. */
 {
 pgSnpMethods(track);
+// Disinherit next/prev flag and methods since we don't support next/prev:
+track->nextExonButtonable = FALSE;
+track->nextPrevExon = NULL;
+track->nextPrevItem = NULL;
 track->loadItems = vcfTabixLoadItems;
 track->canPack = TRUE;
 }
 
 #else // no USE_TABIX:
 
 // If code was not built with USE_TABIX=1, but there are vcfTabix tracks, display a message
 // in place of the tracks (instead of annoying "No track handler" warning messages).
 
 static void drawUseVcfTabixWarning(struct track *tg, int seqStart, int seqEnd, struct hvGfx *hvg,
 				   int xOff, int yOff, int width, MgFont *font, Color color,
 				   enum trackVisibility vis)
 /* Draw a message saying that the code needs to be built with USE_TABIX=1. */
 {
 char message[512];