rem: DEBUG_INIT(CF_PRIVATE, NULL);
add: DEBUG_INIT(NULL);
context: walk_volume_recognition_sequence(int device, off_t offset, uint32 blockSize, uint32 blockShift){	DEBUG_INIT(CF_PRIVATE, NULL);	// vrs starts at block 16. Each volume structure descriptor (vsd)	// should be one block long. We're expecting to find 0 or more iso9660	// vsd's followed by some ECMA-167 vsd's.	MemoryChunk chunk(blockSize);	status_t error = chunk.InitCheck();	if (!error) {		bool foundISO = false;		bool foundExtended = false;		bool foundECMA167 = false;		bool foundECMA168 = false;		bool foundBoot = false;		for (uint32 block = 16; true; block++) {	    	PRINT(("block %ld: ", block))			off_t address = (offset + block) << blockShift;			ssize_t bytesRead = read_pos(device, address, chunk.Data(), blockSize);			if (bytesRead == (ssize_t)blockSize)		    {		    	volume_structure_descriptor_header* descriptor =		    	  reinterpret_cast<volume_structure_descriptor_header*>(chunk.Data());				if (descriptor->id_matches(kVSDID_ISO)) {					SIMPLE_PRINT(("found ISO9660 descriptor\n"));					foundISO = true;				} else if (descriptor->id_matches(kVSDID_BEA)) {					SIMPLE_PRINT(("found BEA descriptor\n"));					foundExtended = true;				} else if (descriptor->id_matches(kVSDID_TEA)) {					SIMPLE_PRINT(("found TEA descriptor\n"));					foundExtended = true;				} else if (descriptor->id_matches(kVSDID_ECMA167_2)) {					SIMPLE_PRINT(("found ECMA-167 rev 2 descriptor\n"));					foundECMA167 = true;				} else if (descriptor->id_matches(kVSDID_ECMA167_3)) {					SIMPLE_PRINT(("found ECMA-167 rev 3 descriptor\n"));					foundECMA167 = true;				} else if (descriptor->id_matches(kVSDID_BOOT)) {					SIMPLE_PRINT(("found boot descriptor\n"));					foundBoot = true;				} else if (descriptor->id_matches(kVSDID_ECMA168)) {					SIMPLE_PRINT(("found ECMA-168 descriptor\n"));					foundECMA168 = true;				} else {					SIMPLE_PRINT(("found invalid descriptor, id = `%.5s'\n", descriptor->id));					break;				}			} else {				SIMPLE_PRINT(("read_pos(pos:%Ld, len:%ld) failed with: 0x%lx\n", address,				        blockSize, bytesRead));				break;			}		}				// If we find an ECMA-167 descriptor, OR if we find a beginning		// or terminating extended area descriptor with NO ECMA-168		// descriptors, we return B_OK to signal that we should go		// looking for valid anchors.		error = foundECMA167 || (foundExtended && !foundECMA168) ? B_OK : B_ERROR;		}		RETURN(error);}