Bdale Garbee writes:
> Sure, I can apply your patch in the Debian cpmtools package, since
> it has been accepted upstream. I try to avoid forks, but gaining
> quicker access to something that is coming in upstream's next
> release seems good.
OK, here it is.
It's expected to be released in cpmtools 2.24.
Subject: libdsk: reset geometry if autoprobe isn't sane
So that weirdness from any misfiring auto-geometry heuristic in LibDsk
doesn't cause trouble later. (We were overwriting the most common
parameters, but not all of them.)
(Triggered by Debian bug #1079619, where a spurious dg_sidedness caused
trouble after LibDsk's Opus Discovery heuristic misfired -- that
heuristic has been improved in libdsk 1.5.20, but this change provides
defence in depth.)
---
device_libdsk.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/device_libdsk.c b/device_libdsk.c
index 7baaed4..82b79d1 100644
--- a/device_libdsk.c
+++ b/device_libdsk.c
@@ -72,6 +72,7 @@ const char *Device_open(struct Device *this, const char *filename, int mode, con
const char *Device_setGeometry(struct Device *this, int secLength, int sectrk, int tracks, off_t offset, const char *libdskGeometry)
{
char *boo;
+ int probeOk;
this->secLength=secLength;
this->sectrk=sectrk;
@@ -85,11 +86,22 @@ const char *Device_setGeometry(struct Device *this, int secLength, int sectrk, i
return lookupFormat(&this->geom, libdskGeometry);
}
+ /* Did the autoprobe guess right about the number of sectors & cylinders? */
+ if (this->geom.dg_cylinders * this->geom.dg_heads == tracks)
+ {
+ probeOk = 1;
+ }
+ else
+ {
+ /* If not, reset to a minimal geometry (to undo any randomness from
+ * a failed autoprobe), and guess some parameters */
+ probeOk = 0;
+ dg_stdformat(&this->geom, FMT_180K, NULL, NULL);
+ }
this->geom.dg_secsize = secLength;
this->geom.dg_sectors = sectrk;
- /* Did the autoprobe guess right about the number of sectors & cylinders? */
- if (this->geom.dg_cylinders * this->geom.dg_heads == tracks) return NULL;
- /* Otherwise we guess: <= 43 tracks: single-sided. Else double. This
+ if (probeOk) return NULL;
+ /* We guess: <= 43 tracks: single-sided. Else double. This
* fails for 80-track single-sided if there are any such beasts */
if (tracks <= 43)
{
--
2.30.2
