User is always asked to update when config resembles JSON

Diagnostic output

jrnl: v4.1
Python: 3.11.9 (main, Apr  2 2024, 08:25:04) [GCC 13.2.0]
OS: Linux 6.6.32

Current Behavior

Whenever the config file resembles JSON, the user is prompted to update, regardless of if version is set.

Expected Behavior

As YAML is a superset of JSON (so this is a valid config), and "version": "v4.1" is set, I would expect not to be prompted to update.

Repro Steps

Set your config to a JSON-style YAML file. For reference, the following is my config. (Since it was generated by my operating system, it hasn't been given any readable formatting.)

{"colors":{"body":"none","date":"black","tags":"yellow","title":"cyan"},"default_hour":9,"default_minute":0,"editor":"hx","encrypt":false,"highlight":true,"indent_character":"|","journals":{"default":{"journal":"~/Documents/jrnl/journal.txt"},"food":{"journal":"~/Documents/jrnl/food.txt"}},"linewrap":79,"tagsymbols":"#@","template":false,"timeformat":"%F %r","version":"v4.1"}

Run jrnl.

Debug output

[13:46:01] DEBUG    Logging start                                                     main.py:32
           DEBUG    Parsed args:                                                      main.py:42
                    Namespace(debug=True, preconfig_cmd=None, postconfig_cmd=None,
                    filename=None, template=None, on_date=None,
                    today_in_history=False, month=None, day=None, year=None,
                    start_date=None, end_date=None, contains=None, strict=False,
                    starred=False, tagged=False, limit=None, excluded=[], edit=False,
                    delete=False, change_time=None, export=False, tags=False,
                    short=False, config_override=[], config_file_path='', text=[],
                    exclude_starred=False, exclude_tagged=False)
           DEBUG    Reading configuration from file                                install.py:91
                    /home/kaylee/.config/jrnl/jrnl.yaml
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃  Welcome to jrnl v4.1!                                                           ┃
┃                                                                                  ┃
┃  It looks like you've been using an older version of jrnl until now. That's      ┃
┃  okay - jrnl will now upgrade your configuration and journal files. Afterwards   ┃
┃  you can enjoy all of the great new features that come with jrnl 2:              ┃
┃                                                                                  ┃
┃  - Support for storing your journal in multiple files                            ┃
┃  - Faster reading and writing for large journals                                 ┃
┃  - New encryption back-end that makes installing jrnl much easier                ┃
┃  - Tons of bug fixes                                                             ┃
┃                                                                                  ┃
┃  Please note that jrnl 1.x is NOT forward compatible with this version of jrnl.  ┃
┃  If you choose to proceed, you will not be able to use your journals with        ┃
┃  older versions of jrnl anymore.                                                 ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃  The following journals will be upgraded to jrnl v4.1:  ┃
┃  default -> /home/kaylee/Documents/jrnl/journal.txt     ┃
┃  food    -> /home/kaylee/Documents/jrnl/food.txt        ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
Continue upgrading jrnl? [y/N] N
┏━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃  jrnl was NOT upgraded  ┃
┗━━━━━━━━━━━━━━━━━━━━━━━━━┛

Other Information

It appears the culprit is is_old_version, which only checks if the config is JSON without considering the version field.

jrnl-org / jrnl