fix INT21.7303 return cluster count one too high

boeckmann · PerditionC · commit 14c6201ceb28 · 2025-11-23T16:03:55.000-05:00
fixes #194
diff --git a/kernel/dosfns.c b/kernel/dosfns.c
@@ -954,7 +954,7 @@ COUNT DosGetExtFree(BYTE FAR * DriveString, struct xfreespace FAR * xfsp)
       return DE_INVLDDRV;
     xfsp->xfs_secsize = dpbp->dpb_secsize;
     xfsp->xfs_totalclusters =
-        (ISFAT32(dpbp) ? dpbp->dpb_xsize : dpbp->dpb_size);
+        (ISFAT32(dpbp) ? dpbp->dpb_xsize : dpbp->dpb_size) - 1;
     xfsp->xfs_freeclusters = dos_free(dpbp);
     xfsp->xfs_clussize = dpbp->dpb_clsmask + 1;
   }

Original file line number	Diff line number	Diff line change
`@@ -954,7 +954,7 @@ COUNT DosGetExtFree(BYTE FAR * DriveString, struct xfreespace FAR * xfsp)`
`954`	`954`	`return DE_INVLDDRV;`
`955`	`955`	`xfsp->xfs_secsize = dpbp->dpb_secsize;`
`956`	`956`	`xfsp->xfs_totalclusters =`
`957`		`- (ISFAT32(dpbp) ? dpbp->dpb_xsize : dpbp->dpb_size);`
	`957`	`+ (ISFAT32(dpbp) ? dpbp->dpb_xsize : dpbp->dpb_size) - 1;`
`958`	`958`	`xfsp->xfs_freeclusters = dos_free(dpbp);`
`959`	`959`	`xfsp->xfs_clussize = dpbp->dpb_clsmask + 1;`
`960`	`960`	`}`