Merge branch 'jk/check-corrupt-objects-carefully'

Have the streaming interface and other codepaths more carefully examine for corrupt objects. * jk/check-corrupt-objects-carefully: clone: leave repo in place after checkout errors clone: run check_everything_connected clone: die on errors from unpack_trees add tests for cloning corrupted repositories streaming_write_entry: propagate streaming errors add test for streaming corrupt blobs avoid infinite loop in read_istream_loose read_istream_filtered: propagate read error from upstream check_sha1_signature: check return value from read_istream stream_blob_to_fd: detect errors reading from stream