Three fixes landing the PDF-slicing set coherently:
- bisect_slice read raw container bytes, so the adaptive-retry path (a lone oversized
slice that still overflows, #2880) searched for the newline cut in binary coordinates
and could cut mid-line for a compressed PDF. Index unit_source_text instead, matching
read_slice_text and expand_oversized_files; any converter failure falls back to None.
- #2900's test asserted a PDF is not splittable, which #2906 overturns; rewrite it to
guard the real invariant (an image has no addressable text and is never sliced). The
unreadable-PDF passthrough case is covered by test_pdf_slicing.
- add a bisect_slice-on-PDF regression test: the cut lands on an extracted-text line
boundary and the halves tile the slice exactly.
safishamsi
ada1c095ab