b86309542d
The UC2 container stores 32-bit offsets; ftell results were cast to unsigned at four sites, so positions past 4 GiB would wrap silently and corrupt the directory. tell32() now reports the format limit and exits. Also checks the ftell result reserved for the ingest manifest instead of seeking to -1 on error. Multi-volume spanning (2b65f0a) remains the route for larger payloads.