Fix for Jpeg Metadata Decoding with unknown APP13 profile

[mkehoe]

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Description

Fix for Jpeg Decoding Metadata for unknown APP13 profiles. Without this fix the parser will continue parsing any non-Photoshop profile looking for markers and under the right circumstances cause the SOS marker to get missed. Sorry not able to provide the image where this issue was originally encountered for a test case.

[CLAassistant]

All committers have signed the CLA.

[JimBobSquarePants]

Thanks for your submission @mkehoe we really appreciate it.

Sorry not able to provide the image where this issue was originally encountered for a test case.

I'm assuming this is due to privacy concerns? Is so, no worries. The change is a reasonable optimization without the test image.

[codecov]

Codecov Report

Merging #1931 (fab1691) into master (576a69f) will increase coverage by 0%.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           master   #1931   +/-   ##
======================================
  Coverage      88%     88%           
======================================
  Files         966     966           
  Lines       51320   51321    +1     
  Branches     6397    6397           
======================================
+ Hits        45188   45189    +1     
  Misses       5074    5074           
  Partials     1058    1058           

Flag	Coverage Δ
unittests	88% <100%> (+<1%)	⬆️

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Impacted Files	Coverage Δ
src/ImageSharp/Formats/Jpeg/JpegDecoderCore.cs	89% <100%> (+<1%)	⬆️

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