Some filenames are mistakingly assumed to be URLs

[thbar]

A corollary of #4 is that if you generate a filename from a url, replacing all non-word characters by a - (e.g. Regex.replace(~r/\W/, url, "-")), you will get this filename (a common technique to generate local filesystem cache of remote files):

https---opendata-lillemetropole-fr-api-datasets-1-0-transport_arret_transpole-point-alternative_exports-gtfs_zip

Feeding it as the --input to gtfs-geojson gives the following error:

RUST_BACKTRACE=1 ../gtfs-to-geojson/target/release/gtfs-geojson --input https---opendata-lillemetropole-fr-api-datasets-1-0-transport_arret_transpole-point-alternative_exports-gtfs_zip
thread 'main' panicked at 'The GTFS file is not well formated.: Fetch(reqwest::Error { kind: Builder, source: RelativeUrlWithoutBase })', src/main.rs:40:6
stack backtrace:
   0: rust_begin_unwind
             at /rustc/53cb7b09b00cbea8754ffb78e7e3cb521cb8af4b/library/std/src/panicking.rs:493:5
   1: core::panicking::panic_fmt
             at /rustc/53cb7b09b00cbea8754ffb78e7e3cb521cb8af4b/library/core/src/panicking.rs:92:14
   2: core::result::unwrap_failed
             at /rustc/53cb7b09b00cbea8754ffb78e7e3cb521cb8af4b/library/core/src/result.rs:1355:5
   3: gtfs_geojson::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

The feature at https://github.com/rust-transit/gtfs-structure#feature-read-url kicks in an reqwest attempts to download from what it believes to be a broken url.

Nothing critical at this point, I'm just opening the ticket in case a user later wonders about the behaviour, and maybe I'll come back to fix it in the future.