76541502f60ad17d6f23dec970af30a07e9ebc84
braney
  Fri Sep 14 15:59:34 2018 -0700
oops, forgot to close bigWig files after reading. #22088

diff --git src/hg/lib/mathWig.c src/hg/lib/mathWig.c
index 12c790f..5c0de5f 100644
--- src/hg/lib/mathWig.c
+++ src/hg/lib/mathWig.c
@@ -134,31 +134,42 @@
 
 struct wiggle *nextWiggle;
 for(wiggle = wiggleList; wiggle; wiggle = nextWiggle)
     {
     nextWiggle = wiggle->next;
     if (wiggle->span == minSpan)
         getWigDataFromFile(wiggle, array, winStart, winEnd);
     freez(&wiggle);
     }
 }
 
 void getBigWigData(char *file, char *chrom, unsigned winStart, unsigned winEnd, double *array)
 /* Query a bigBed file to find the wiggle values we need for a specified range. */
 {
 struct lm *lm = lmInit(0);
-struct bbiFile *bwf = bigWigFileOpen(hReplaceGbdb(file));
+static char *fileName = NULL;
+static struct bbiFile *bwf = NULL;
+
+if ((fileName == NULL) || differentString(fileName, file))
+    {
+    if (bwf != NULL)
+        bbiFileClose(&bwf);
+
+    fileName = cloneString(file);
+    bwf = bigWigFileOpen(hReplaceGbdb(file));
+    }
+
 struct bbiInterval *iv, *ivList = bigWigIntervalQuery(bwf, chrom, winStart, winEnd, lm);
 unsigned width = winEnd - winStart;
 
 for (iv = ivList; iv != NULL; iv = iv->next)
     {
     unsigned start = max(0, iv->start - winStart);
     unsigned end = min(width, iv->end - winStart);
     int ii;
 
     for (ii = start; ii < end; ii++)
         array[ii] = iv->val;
     }
 }
 
 double *mathWigGetValues(char *db, char *equation, char *chrom, unsigned winStart, unsigned winEnd, boolean missingIsZero)