fix: recover from corrupted persist file at package load (upstream #45)

Issue #45 (2021): persist-load raised End of file during parsing
at persist.el:413 in some configurations, likely from a corrupted
persist data file.  Pre-fix, this propagated up through the
top-level (persist-defvar org-drill-sm5-optimal-factor-matrix ...)
form at file-load time and broke the entire package's load.

Wrapped the persist-defvar form in condition-case.  On failure, the
matrix falls back to a fresh nil binding via plain defvar, and a
message tells the user what happened.  org-drill continues to load
normally.

0 files changed, 0 insertions, 0 deletions