The random-access demuxer added two surfaces with no gate behind them. A
download stored through SAF arrives as content://, where an index read has to
open a second descriptor while the loader holds one, and the AVIO callbacks
are reached only by name from C++, so R8 may rename them while every debug
check passes -- the shape #1703 shipped with.
FfmpegExtractorSeekTest now runs the cued fixture over a content:// URI
served by a test-only provider, and FfmpegDemuxerReachabilityTest drives
nativeOpen plus a seek through a media3-free byte source so it can run
minified. Wired into the existing R8 reachability target; verified it fails
when the FfmpegDemuxerJni$Input keep rule is removed.
edde746
fe9d9d5e7d