CP/M disk detection - if the first 256 bytes of the file entries contained

an empty file entry, the routine would loop indefinately.
This commit is contained in:
Robert Greene 2003-12-22 07:14:10 +00:00
parent d1f9e3a395
commit b4951201b5

View File

@ -549,17 +549,18 @@ public class Disk {
for (int i=0; i<CpmFileEntry.ENTRY_LENGTH; i++) {
e5count+= bytes[offset+i] == 0xe5 ? 1 : 0;
}
if (e5count == CpmFileEntry.ENTRY_LENGTH) continue;
// Check user number. Should be 0-15 or 0xE5
if (bytes[offset] > 15 && bytes[offset] != 0xe5) return false;
// Validate filename has highbit off
for (int i=0; i<8; i++) {
if (bytes[offset+1+i] > 127) return false;
if (e5count != CpmFileEntry.ENTRY_LENGTH) { // Not all bytes were 0xE5
// Check user number. Should be 0-15 or 0xE5
if (bytes[offset] > 15 && bytes[offset] != 0xe5) return false;
// Validate filename has highbit off
for (int i=0; i<8; i++) {
if (bytes[offset+1+i] > 127) return false;
}
// Extent should be 0-31 (low = 0-31 and high = 0)
if (bytes[offset+0xc] > 31 || bytes[offset+0xe] > 0) return false;
// Number of used records cannot exceed 0x80
if (bytes[offset+0xf] > 0x80) return false;
}
// Extent should be 0-31 (low = 0-31 and high = 0)
if (bytes[offset+0xc] > 31 || bytes[offset+0xe] > 0) return false;
// Number of used records cannot exceed 0x80
if (bytes[offset+0xf] > 0x80) return false;
// Next entry
offset+= CpmFileEntry.ENTRY_LENGTH;
}