Show friendly error for bad MARC start position

[Anand Chitipothu]

/show-marc is raising internal errors when the MARC content is invalid. It should rather display an error message or 404.

http://openlibrary.org/show-marc/childrensrhymesc00ford_meta.mrc:0:1192

It should also handle the bad ranges. For example, http://openlibrary.org/show-marc/marc_records_scriblio_net/part29.dat:7383350:445 works fine. But If I change the length to 443, it fails with internal error. I think it should say "404 Not Found".

[Edward Betts (edwardbetts)]

I added a workaround for this example:

http://openlibrary.org/show-marc/childrensrhymesc00ford_meta.mrc:0:1192

It now redirects to here:

http://openlibrary.org/show-records/ia:childrensrhymesc00ford

See the code for full details.

[George (george-archive)]

Another e.g. http://openlibrary.org/show-records/marc_university_of_toronto/uoft.marc:160210883:1130

/upstream/templates/showmarc.tmpl: error in processing template: IndexError: string index out of range (falling back to default template)
/opt/openlibrary/production/openlibrary/plugins/upstream/templates/showmarc.html: error in processing template: IndexError: string index out of range (falling back to default template)

[Edward Betts (edwardbetts)]

I'm not seeing an error with that University of Toronto link.

[Edward Betts (edwardbetts)]

Changing the length doesn't through an error anymore. I need to produce a nicer error when you pass an invalid start position.