re: reconcile the 49.6/92.3 split -- same numerator, and my explanation of it was wrong

sylpheed-port reconciled the population gap exactly and I reproduced it: filtering
max_t > 0 gives 1781 records and 92.3 %, their figures precisely. Same numerator,
1643, both ways.

My stated explanation was wrong. I said the scan requires a timed keyframe; it does
not, because .max() returns Some(0) rather than None for records whose keyframes are
all at time 0, so 1530 records where the question has no content stayed in my
denominator and counted as failures by construction.

The conclusion is untouched -- +0x04 is 0 % under either denominator.

Records their diagnosis of why it stayed invisible: the numerator agreed to the
unit, so a shared 1643 read as agreement and neither of us looked there. And both
halves needed a qualifier neither carried -- 92.3 % is of the records where the
question is meaningful, not of nested records.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Wuu56cE8vJGTBtn1ppsk8v

crates/sylpheed-formats/examples/loop_length_offset_discriminates.rs

@@ -45,6 +45,10 @@ fn main() {
                     .flat_map(|el| el.keyframes.iter().filter_map(|k| k.time))
                     .max();
                 let Some(max_t) = max_t else { continue };
+                // sylpheed-port's reconciliation: max_t == 0 makes "does the word
+                // equal the largest keyframe time?" vacuous, and those records were
+                // silently in my denominator. Filter them and the counts must meet.
+                if std::env::var("MEANINGFUL_ONLY").is_ok() && max_t == 0 { continue }
                 for (i, o) in offsets.iter().enumerate() {
                     if let Some(w) = be32(rec, *o) {
                         stat[i].0 += 1;