Back-port actions and fuzzer to 0.27-maintenance

[kevinbackhouse]

I would like to run all the automated checks that we have developed for the main branch on the 0.27-maintenance branch before we release 0.27.5. This PR mostly just copies the contents of the .github and fuzz sub-directories from the main branch onto the 0.27-maintenance branch. There are a few other minor changes :

• CMakeLists.txt, cmake/compilerFlags.cmake: add the fuzzer to cmake.
• src/basicio.cpp, src/jpgimage.cpp, src/pngimage.cpp: don't call memcpy or memcmp with a zero size argument to avoid a UBSAN false positive (complaining about one of the pointer arguments being NULL).
• src/image.cpp, src/jpgimage.cpp: some debug messages were accidentally switched on by default, which was spamming the fuzzer logs.
• The build commands are the same as the main branch, except BMFF is off by default.
• I disabled all "schedule" triggers in the actions because we don't need to build the 0.27-maintenance branch on a daily basis.

[codecov]

Codecov Report

Merging #1854 (df011fc) into 0.27-maintenance (58fb9f8) will decrease coverage by 19.31%.
The diff coverage is 40.28%.

@@                  Coverage Diff                  @@
##           0.27-maintenance    #1854       +/-   ##
=====================================================
- Coverage             65.47%   46.16%   -19.32%     
=====================================================
  Files                   159      145       -14     
  Lines                 23104    22460      -644     
  Branches                  0    11514    +11514     
=====================================================
- Hits                  15128    10368     -4760     
+ Misses                 7976     6647     -1329     
- Partials                  0     5445     +5445     

Impacted Files	Coverage Δ
include/exiv2/basicio.hpp	75.00% <ø> (ø)
include/exiv2/error.hpp	62.96% <ø> (-28.35%)	⬇️
include/exiv2/exif.hpp	100.00% <ø> (ø)
include/exiv2/image.hpp	100.00% <ø> (ø)
include/exiv2/iptc.hpp	100.00% <ø> (ø)
include/exiv2/metadatum.hpp	40.00% <ø> (-60.00%)	⬇️
include/exiv2/pgfimage.hpp	0.00% <ø> (-100.00%)	⬇️
include/exiv2/rwlock.hpp	100.00% <ø> (ø)
include/exiv2/slice.hpp	89.83% <ø> (-8.32%)	⬇️
include/exiv2/xmp_exiv2.hpp	83.33% <ø> (-8.98%)	⬇️
... and 257 more

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[kevinbackhouse]

All the builds are passing now, except "Win Matrix on PRs / Win10 Arch: x64 BuildType:Debug - SHARED:OFF".
It looks like the solution is in commit 582edd3, but I'm not sure if I need all of that or only the change in samples/CMakeLists.txt.

[hassec]

Suggested change

	cmake -GNinja -DCMAKE_BUILD_TYPE=${{matrix.build_type}} -DBUILD_SHARED_LIBS=${{matrix.shared_libraries}} -DEXIV2_ENABLE_PNG=ON -DEXIV2_ENABLE_WEBREADY=ON -DEXIV2_ENABLE_CURL=ON -DEXIV2_BUILD_UNIT_TESTS=ON -DEXIV2_ENABLE_BMFF=OFF -DEXIV2_TEAM_WARNINGS_AS_ERRORS=ON -DCMAKE_INSTALL_PREFIX=install -DCMAKE_CXX_FLAGS="-Wno-deprecated-declarations" -DCMAKE_CXX_STANDARD=11 ..
	cmake -GNinja -DCMAKE_BUILD_TYPE=${{matrix.build_type}} -DBUILD_SHARED_LIBS=${{matrix.shared_libraries}} -DEXIV2_ENABLE_PNG=ON -DEXIV2_ENABLE_WEBREADY=ON -DEXIV2_ENABLE_CURL=ON -DEXIV2_BUILD_UNIT_TESTS=ON -DEXIV2_ENABLE_BMFF=OFF -DEXIV2_TEAM_WARNINGS_AS_ERRORS=ON -DCMAKE_INSTALL_PREFIX=install -DCMAKE_CXX_FLAGS="-Wno-deprecated-declarations" -DCMAKE_CXX_STANDARD=98 ..

on 0.27 it should be c++98 right?

[kevinbackhouse]

I couldn't get the build to work with conan on macOS, so I tried removing the conan step. But that meant that I had to add brew install googletest to the installation steps and that seems to have given me a version of gtest that will only build with C++11. I figure that it's fairly harmless to use C++11 here, because I'm just passing it on the command-line rather than modifying any of the CMakeLists.txt files.

Do you know the best way to build on macOS?

[hassec]

Probably fine, considering that we are just trying to run these checks.

I unfortunately also don't know much about the build config, especially for MacOS and Win.
@piponazo was the one who set most of this up AFAIK

[kevinbackhouse]

I think this is ready now. The first 4 commits are cherry-picked from main to fix various build problems. The 5th commit adds the Actions and fuzz directory.

The Actions are currently building with -DEXIV2_ENABLE_BMFF=OFF because I mistakenly thought that BMFF was not enabled 0.27. I will enable BMFF after #1855 is merged.