:wa and :qa report 'No file name for buffer [corn.renderer.bufnr]' and 'No write since last change for buffer "[No Name]"

[dpvanbalen]

Even when disabling every plugin aside from corn (with default configuration) and LSPs (to have diagnostics for corn), I have the following issue:

1. open a file with a diagnostic
2. have the diagnostic show up in a corner
3. run wa: it errors with "no file time for buffer 2" (and require("corn.renderer").bufnr is always 2)
4. run qa: it errors with "No write since last change for buffer "[No Name]" (which turns out to also be buffer 2, containing the diagnostic).

The error persists even when the diagnostic is no longer shown in the corner (e.g. when navigating to a different line or file).

NVIM v0.12.4
Build type: RelWithDebInfo
LuaJIT 2.1.1783773675