Session file is broken after vim update

[eight04]

In newer vim version, they changed the script version and some syntax generated by obsession becomes syntax error.

See tpope/vim-obsession#87

To avoid this issue, users have to:

1. Update vim.
2. Update obsession with that fix.
3. Load the session (in old syntax).
4. Save the session (in new syntax).

If a user (me) updated vim without updating obsession:

1. Update vim.
2. Load the session (in old syntax).
3. Save the session (mixed with new syntax and old syntax).

An error will occur next time loading the session.

WDYT to add a check/fix before prosession loading the session file? Then the bug won't affect prosession users even without that fix.

[dhruvasagar]

@eight04 Thanks for reporting this, i'll take a deeper look. Ideally I would think this belongs to vim-obsession to take care of but if I can add some checks around it we could do that.