Don't set CMAKE_DEBUG_POSTFIX if in a subproject

[Debitsch-Faro]

Don't add the CMAKE_DEBUG_POSTFIX variable to the cache

When using OpenEXR as an subproject this overwrites the settings of other subprojects.

Change header file only when necessary

Cmake configure rewrites the libdeflate lib_common.h header file. This triggers rebuilds when reconfiguring a cmake project. E.g. The cmake tools of vscode trigger a reconfigure of a project when something is changed in one of the projects cmake files. Then the header file is written and a rebuild of the deflate library is triggered.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: Debitsch-Faro (47e50ce, 3c30370, 29e5f45)

[meshula]

I think this looks good. Could I ask for a second set of eyes on the DEFLATE change please?

[cary-ilm]

This looks good to me, thanks.

@Debitsch-Faro, our project policy is to require a Contributor License Agreement (CLA) and Digital Certificate of Origin (DCO), i.e. signed commits, hence the check failures.

Could you kindly sign the CLA through the form at the red "NOT COVERED" box above? And for the DCO, please amend your commit with the -s option, which will add the "signed-off-by " onto the commit message:

git commit --amend -s

You'll obviously need to do a git push --force to replace the existing commit.

Thanks for the contribution, and your patience with the contribution requirements.

[Debitsch-Faro]

Hope this works now. This is my first github pull-request. Sorry for any extra work from your side.

[cary-ilm]

Close! The CLA is in place, but unfortunately all 3 commits need to be signed. to get past the DCO check. Probably the easiest thing to do is merge the 3 commits into a single one, then sign that one. I use git rebase -i HEAD~3, then follow the instructions in the editor, but there are probably other ways as well. Thanks!

[cary-ilm]

One additional small request: can you change the name of the PR to something more descriptive, e.g. "Don't set CMAKE_DEBUG_POSTFIX if in a subproject". The PR name will appear in the release notes, and "Fix 1981" won't mean much. Use the "edit" button to the right of the PR title. Thanks!