Merge pull request #1498 from blankenberg/tab_mime

[16.01] Set mime type when previewing tabular data that has > 50 columns, but < 1000000 bytes.

lib/galaxy/datatypes/tabular.py

@@ -81,6 +81,7 @@ class TabularData( data.Text ):
             # For now, default to the old behavior, ugly as it is.  Remove this after adding 'matrix'.
             max_peek_size = 1000000  # 1 MB
             if os.stat( dataset.file_name ).st_size < max_peek_size:
+                self._clean_and_set_mime_type( trans, dataset.get_mime() )
                 return open( dataset.file_name )
             else:
                 trans.response.set_content_type( "text/html" )