We ran Norton 3.0 on a Power Macintosh and did not get the invalid file length error for the QuickDraw GX extension. However, we had used ResEdit to look at the extension before running the Norton utility. ResEdit had to do some minor repairs before it would open the extension.
The first part of the resource fork is a header which contains information about the length of the fork. Specifically, the header contains the offset to the resource map and the length of the map. Since the resource map is at the end of the fork, the offset to the resource map and the length of the resource map should add up to the length of the resource fork.
However, the resource fork of the QuickDraw GX extension has some extra bytes added after the resource map. The data in the resource fork is not corrupted in any way and the Resource Manager is not affected by the extra bytes.
We contacted Symantec and were told that Norton compares the actual fork length to the sum of the offset to the resource map and the length of the resource map. If these values are not equal, Norton reports an incorrect physical length for the file. They are also aware of this error being reported for the QuickDraw GX extension, but have not determined what to do about it at this time.
Symantec suggests we tell anyone who calls about this message to ignore it for now, but only if the message pertains to the QuickDraw GX extension.
Apple engineering says that the extra bytes in the QuickDraw GX resource fork are due to the compression scheme used to compress the resources. They are looking into correcting the problem but it is not a high priority since the problem does not cause any side effects except for confusing some disk repair utilities.
Article Change History:
15 Feb 1995 - Reviewed for technical accuracy, revised System 7.5 keyword.
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