Merge pull request #1930 from mvdbeek/more_bytestring_for_pysam

[16.01] Ensure chrom, start, end as bytestring in BamDataProvider

lib/galaxy/visualization/data_providers/genome.py

@@ -890,6 +890,9 @@ class BamDataProvider( GenomeDataProvider, FilterableMixin ):
         """
 
         # Fetch and return data.
+        chrom = str(chrom)
+        start = int(start)
+        end = int(end)
         try:
             data = data_file.fetch( start=start, end=end, reference=chrom )
         except ValueError: