ae0555edbf3e9bf3d9e05d57786f801ddabe82ee
braney
  Wed Mar 1 12:31:11 2017 -0800
put out a warning if maf summary information is missing, but needed #18950

diff --git src/hg/hgTracks/wigMafTrack.c src/hg/hgTracks/wigMafTrack.c
index 1308a98..d28cc6e 100644
--- src/hg/hgTracks/wigMafTrack.c
+++ src/hg/hgTracks/wigMafTrack.c
@@ -972,31 +972,34 @@
 
 static void drawScoreOverviewBig( struct track *track,  int height,
                                int seqStart, int seqEnd,
                                struct hvGfx *hvg, int xOff, int yOff,
                                int width, MgFont *font,
                                Color color, Color altColor,
                                enum trackVisibility vis)
 /* Draw density plot or graph for overall maf scores rather than computing
  * by sections, for speed.  Don't actually load the mafs -- just
  * the scored refs from the table.
  */
 {
 struct lm *lm = lmInit(0);
 char *fileName = trackDbSetting(track->tdb, "summary");
 if (fileName == NULL)
+    {
+    warn("cannot find summary information in trackDb for track '%s'", track->track);
     return;
+    }
 struct bbiFile *bbi =  bigBedFileOpen(fileName);
 struct bigBedInterval *bb, *bbList =  bigBedIntervalQuery(bbi, chromName, seqStart, seqEnd, 0, lm);
 char *bedRow[7];
 char startBuf[16], endBuf[16];
 double scale = scaleForPixels(width);
 
 for (bb = bbList; bb != NULL; bb = bb->next)
     {
     bigBedIntervalToRow(bb, chromName, startBuf, endBuf, bedRow, ArraySize(bedRow));
     struct mafSummary *ms;
     ms = mafSummaryLoad(bedRow);
     drawScore(ms->score, ms->chromStart, ms->chromEnd, seqStart, scale,
                     hvg, xOff, yOff, height, color, vis);
 
     }