Throw a JpegError when a JPEG image has no frame data (issue 17302)

[Snuffleupagus]

Given that there's nothing to parse in this case, since we're dealing with an invalid JPEG image, throwing an explicit Error makes sense here.

[Snuffleupagus]

/botio test

[moz-tools-bot]

From: Bot.io (Linux m4)

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Received

Command cmd_test from @Snuffleupagus received. Current queue size: 0

Live output at: http://54.241.84.105:8877/f2838404eff167f/output.txt

[moz-tools-bot]

From: Bot.io (Windows)

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Received

Command cmd_test from @Snuffleupagus received. Current queue size: 0

Live output at: http://54.193.163.58:8877/a35fade86eb53ca/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

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Failed

Full output at http://54.241.84.105:8877/f2838404eff167f/output.txt

Total script time: 24.77 mins

• Unit tests: Passed
• Integration Tests: Passed
• Regression tests: FAILED

  different ref/snapshot: 16

Image differences available at: http://54.241.84.105:8877/f2838404eff167f/reftest-analyzer.html#web=eq.log

[moz-tools-bot]

From: Bot.io (Windows)

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Failed

Full output at http://54.193.163.58:8877/a35fade86eb53ca/output.txt

Total script time: 34.43 mins

• Unit tests: Passed
• Integration Tests: Passed
• Regression tests: FAILED

  different ref/snapshot: 21

Image differences available at: http://54.193.163.58:8877/a35fade86eb53ca/reftest-analyzer.html#web=eq.log

[calixteman]

I'm not sure that it's so useful to throw here instead of throwing at the next line...
That said it doesn't really hurt.
LGTM. Thank you.

[Snuffleupagus]

I'm not sure that it's so useful to throw here instead of throwing at the next line...

Agreed; the only reason that I think this makes sense to do here is because we're publishing the PDF.js image decoders separately in pdfjs-dist, see https://github.com/mozilla/pdfjs-dist/tree/master/image_decoders