[1.x] test ABI breakage on 1.x branches

[robUx4]

No description provided.

[robUx4]

Similar to #83

[mbunkus]

BTW, we also have to account for ABI changes that are fine: solely adding new symbols. For example, the abidiff output comparing release 1.6.3 & 1.7.1 lists a lot of added symbol, and the exit code is 4, but those two are actually compatible.

[mbunkus]

The user who suggested abidiff also pointed to two examples. One of them uses a couple of CLI options, one of them that seem relevant to us, too: --no-added-symbols which addresses what I wrote above. Not sure about the others, though.

[robUx4]

The user who suggested abidiff also pointed to two examples. One of them uses a couple of CLI options, one of them that seem relevant to us, too: --no-added-symbols which addresses what I wrote above. Not sure about the others, though.

Yeah I saw but I wasn't sure if it's adding or removing error cases. I'll add it here (and there) once I get it to detect ABI changes...

[robUx4]

@mbunkus aren't those changes ABI changes 1d132ed ? It doesn't detect them 😞

[mbunkus]

I would have thought so, yeah, at least renaming the GetParentCluster function. 😕

[robUx4]

I added more odd changes (following https://community.kde.org/Policies/Binary_Compatibility_Issues_With_C++) and it still doesn't see anything :/ It's odd because it worked well on libebml.

I also checked it's really comparing different builds of different libraries (changing the VERSION to 8.0.0 was detected from the symbolic links).