JUMBF parsing problem

[Neal Krawetz]

I'm seeing ExifTool (12.64 - 12.68, possibly earlier) complaining about some images with JUMBF:

Warning : Invalid JUMBF sequence number

After the error, ExifTool gives up on parsing the JUMBF data.

Here are two examples. Both contain valid JUMBF records.

https://fotoforensics.com/analysis.php?id=5f3bb859aaca63cb45ecd606c45bdc821633b863.402656&fmt=orig
This image has a properly formatted JUMBF. (My parser isn't seeing any problems, and Adobe's code also parses it properly.)

https://fotoforensics.com/analysis.php?id=641b336f1ab1a497b06ac6172c3958d72966a95e.116137&fmt=orig
This image has an extra four 0x00 bytes at the beginning. Based on the number of pictures I've seen with this initial passing, it looks like it might be a common issue.

[Phil Harvey]

I should have anticipated this.  Numbering errors like this are common.  I'll add a patch to issue a warning but continue.

- Phil