Detects possible FAT geometry in fixed VHDs too #4961
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Since MBR and FAT CHS geometries may differ even with Windows 11 created VHDs, we attempt to read
| vhd->cylinders = sizes[3]; | ||
| vhd->heads = sizes[2]; | ||
| vhd->sectors = sizes[1]; | ||
| vhd->fixedDisk = new imageDisk(file, fileName, vhd->cylinders, vhd->heads, vhd->sectors, 512, true); |
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Does calling new imageDisk() twice safely deletes the previous one?
I think better to check sizes[] and DetectGeometry before new imageDisk
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Obviously, it does not (deleting caused an obscure exception). [*]
DetectGeometry actually requires a valid disk image internally to properly read VHD sectors, that's the reason why I avoided that call in previous commits (having tought at least Windows 1x set MBR CHS == BPB CHS).
Perhaps I'll find another way, if you haven't suggestions.
EDIT:
[*] The exception cause: delete vhd->fixedDisk would call fclose(dskimg), where dskimg is an alias for file object, required by following new imageDisk call.
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Is there really any difference between creating a VHD file in Windows 10 or 11, even with DOSBox-X? |
Yes, if you partition or format, different softwares do different calculations of geometry recorded in MBR and boot sector. |
Since MBR and FAT CHS geometries may differ even with Windows 11 created VHDs, we attempt to read both of them.
Fixes #4958