e469259cebde62bf0bf53f582f7f69ba9a22aebc
braney
  Tue Mar 29 12:28:22 2022 -0700
allow big* tracks with only a bigDataUrl to be used in Extended DNA
coloring page

diff --git src/hg/lib/featureBits.c src/hg/lib/featureBits.c
index 3bd9d92..2478d46 100644
--- src/hg/lib/featureBits.c
+++ src/hg/lib/featureBits.c
@@ -120,34 +120,37 @@
 
 static boolean utr3Qualifier(char *qualifier, char *extra, int *retSize)
 /* Return TRUE if it's a utr3 qualifier. */
 {
 return fetchQualifiers("utr3", qualifier, extra, retSize);
 }
 
 static boolean utr5Qualifier(char *qualifier, char *extra, int *retSize)
 /* Return TRUE if it's a utr5 qualifier. */
 {
 return fetchQualifiers("utr5", qualifier, extra, retSize);
 }
 
 
 
-boolean fbUnderstandTrack(char *db, char *track)
+boolean fbUnderstandTrack(char *db, struct trackDb *tdb)
 /* Return TRUE if can turn track into a set of ranges or bits. */
 {
-struct hTableInfo *hti = hFindTableInfo(db, NULL, track);
+if ((tdb != NULL) && startsWith("big", tdb->type))
+	return TRUE;
+
+struct hTableInfo *hti = hFindTableInfo(db, NULL, tdb->track);
 
 if (hti == NULL)
     return FALSE;
 else
     return hti->isPos;
 }
 
 static void fbAddFeature(char *db, struct featureBits **pList, char *name,
 	char *chrom, int start, int size, char strand, 
 	int winStart, int winEnd)
 /* Add new feature to head of list.  Name can be NULL. */
 {
 struct featureBits *fb;
 int s, e;
 char nameBuf[512];