Zero size read or write should not change drive state.

diff --git a/scsitape.cpp b/scsitape.cpp
index fdc1c0a67c107be4de2dbdfbbbe24058a3062ee9..5cf36641637dfe2f8baec77c64a9f037ad231c0c 100644 (file)
--- a/scsitape.cpp
+++ b/scsitape.cpp
@@ -334,10 +334,12 @@ static int tape_read (struct scsi_data_tape *tape, uae_u8 *scsi_data, int len, b
                                write_log(_T("TAPEEMU READ: Requested %ld, read %ld, pos %lld, %lld remaining.\n"), len, got, pos, zfile_size(tape->zf) - pos);
                } else {
                        got = 0;
-                       uae_u8 *data = xmalloc(uae_u8, len);
-                       if (data) {
-                               got = zfile_fread(data, 1, len, tape->zf);
-                               xfree(data);
+                       if (len > 0) {
+                               uae_u8 *data = xmalloc(uae_u8, len);
+                               if (data) {
+                                       got = zfile_fread(data, 1, len, tape->zf);
+                                       xfree(data);
+                               }
                        }
                }
                tape->file_offset += got;
@@ -563,7 +565,7 @@ int scsi_tape_emulate (struct scsi_data_tape *tape, uae_u8 *cmdbuf, int scsi_cmd
                        goto unloaded;
                if (tape->wp)
                        goto writeprot;
-               if (tape->beom < 1)
+               if (len && tape->beom < 1)
                        tape->beom = 1;
                scsi_len = tape_write (tape, scsi_data, len);
                if (scsi_len < 0)
@@ -582,7 +584,7 @@ int scsi_tape_emulate (struct scsi_data_tape *tape, uae_u8 *cmdbuf, int scsi_cmd
                        goto notape;
                if (tape->unloaded)
                        goto unloaded;
-               if (tape->beom < 0)
+               if (len && tape->beom < 0)
                        tape->beom = 0;
                scsi_len = tape_read (tape, scsi_data, len, &eof);
                if (log_tapeemu)