timestamp_sentence() stripped the trailing space from sentence_text_seg
on every token instead of once when the sentence is emitted, so the
per-sentence raw_text lost all separators ("iphone pro max" became
"iphonepromax"). Trim it only at the sentence boundary, as
timestamp_sentence_en() already does.
When punc_id_list is longer than timestamp_postprocessed (a mismatch
the function already logs a warning for), the entries past the end of
timestamp_postprocessed get timestamp=None from zip_longest. For the
sentence that starts on one of those entries, the is_sentence_start
flag was consumed unconditionally on the first iteration regardless of
whether timestamp was None, so sentence_start kept whatever value was
left over from the previous, unrelated sentence instead of being
reported as unknown.
The sibling function timestamp_sentence already handles this correctly
by resetting sentence_start to None after each flush and only setting
it once a real timestamp shows up. Mirror that logic here instead of
the one-shot is_sentence_start flag.
Before: a trailing sentence whose first word has no timestamp gets
start reused from the previous sentence (wrong, looks valid).
After: start is None for that sentence, matching timestamp_sentence.
Chi-Wei Lee