Read_Shp throws an error if field (by default BtEn) is not in a shapefile with other data fields about sdna_gh HOT 1 CLOSED

In the user provided example file, Read_Shp did not throw an error on field being missing, it issued a warning (below). Subsequently an error was raised, but due to #99, not to the missing field.

        if hasattr(options, 'field') and options.field not in fields:
            msg = 'field: %s not found in shape file fields: %s' 
            msg %= (options.field, fields)
            self.logger.warning(msg)
            warnings.warn(msg)

sDNA_GH.Read_Shp: INFO: Tools == [<ShapefileReader object at 0x000000000000014C>]
sDNA_GH.custom.tools.ShapefileReader: WARNING: field: BtEn not found in shape file fields: ['Shape_Leng', 'ID', 'LConn',---long list---, 'MCF2000', 'DivH2000']
...\UserObjects\sdna-gh\sDNA_GH\custom\tools.py:1: UserWarning: field: BtEn not found in shape file fields: ['Shape_Leng', 'ID', 'LConn', ---long list---, 'MCF2000', 'DivH2000']
#! /usr/bin/awk NR==3
sDNA_GH.custom.tools: ERROR:
The error:
{{ Unable to add polyline to document }}
occurred when adding shape number: 15830 from shapefile: C:...\Unreadable_shapefile\shp_file_test\shp_file_test....shp

Runtime error (Exception):
The error:
{{ Unable to add polyline to document }}
occurred when adding shape number: 15830 from shapefile: C:...\Unreadable_shapefile\shp_file_test\shp_file_test....shp

Traceback:
line 1971, in , "...\UserObjects\sdna-gh\sDNA_GH\custom\tools.py"
line 2012, in call, "...\UserObjects\sdna-gh\sDNA_GH\custom\tools.py"
line 1968, in gdm_of_new_geom_from_group, "...\UserObjects\sdna-gh\sDNA_GH\custom\tools.py"
line 130, in run_tools, "...\UserObjects\sdna-gh\sDNA_GH\custom\skel\tools\runner.py"
line 1237, in script, "...\UserObjects\sdna-gh\sDNA_GH\main.py"
line 375, in RunScript, "...\UserObjects\sdna-gh\sDNA_GH\custom\skel\basic\smart_comp.py"

from sdna_gh.