Define wxIsNaN() as std::isnan() in C++11 mode

[Benjamin Drung]

Audacity (git master) fails to build on Ubuntu 16.04 with g++ 5.3.1:

In file included from /usr/include/wx-3.0/wx/gdicmn.h:23:0,
                 from /usr/include/wx-3.0/wx/utils.h:26,
                 from BlockFile.cpp:51:
BlockFile.cpp: In function ‘void ComputeMinMax256(float*, float*, float*, int*)’:
/usr/include/wx-3.0/wx/math.h:91:31: error: ‘isnan’ was not declared in this scope
     #define wxIsNaN(x) isnan(x)
                               ^
BlockFile.cpp:325:11: note: in expansion of macro ‘wxIsNaN’
       if (wxIsNaN(summary256[3*i+2]))
           ^
/usr/include/wx-3.0/wx/math.h:91:31: note: suggested alternative:
     #define wxIsNaN(x) isnan(x)
                               ^
BlockFile.cpp:325:11: note: in expansion of macro ‘wxIsNaN’
       if (wxIsNaN(summary256[3*i+2]))
           ^
In file included from /usr/include/wx-3.0/wx/math.h:58:0,
                 from /usr/include/wx-3.0/wx/gdicmn.h:23,
                 from /usr/include/wx-3.0/wx/utils.h:26,
                 from BlockFile.cpp:51:
/usr/include/c++/5/cmath:641:5: note: ‘std::isnan’
     isnan(_Tp __x)
     ^
make[3]: *** [audacity-BlockFile.o] Error 1

isnan() is not defined, but std::isnan() is defined. Thus use std::isnan() for all C++11 compilers, since isnan() is part of C++11. The fix was accepted upstream: https://github.com/wxWidgets/wxWidgets/pull/283

[Test Case]

1) Create a git recipe in /tmp/bug-1581807.recipe with following content:

# git-build-recipe format 0.4 deb-version {debupstream}+git{revdate}+r{revno}+{revno:packaging}
lp:audacity f1909cb88e0fa4ecc589e715384b90d8bbfe55e6
merge packaging lp:~audacity-team/audacity/+git/packaging daily-xenial

2) Build a audacity source package:

git-build-recipe --allow-fallback-to-native /tmp/bug-1581807.recipe /tmp/audacity

3) Build the source package on xenial (for example with sbuild):

sbuild -d xenial /tmpfs/audacity_2.1.2+git20160516+r4250+17.dsc

4) You will experience the build failure described above with the unpatched wxwidgets. The build will succeed with the wxwidget patch.

[Regression Potential]

The patch changes C preprocessor definition (and not the run-time). Thus it could break source builds that use wxwidgts as library.

[Benjamin Drung (bdrung)]

Attached wxwidgets3.0_3.0.2+dfsg-1.3ubuntu0.1.debdiff for SRU to xenial.

[Launchpad Janitor (janitor)]

This bug was fixed in the package wxwidgets3.0 - 3.0.2+dfsg-1.3ubuntu1

---------------
wxwidgets3.0 (3.0.2+dfsg-1.3ubuntu1) yakkety; urgency=medium

  * Define wxIsNaN() as std::isnan() in C++11 mode. This fixes the build
    failure of Audacity (Closes: #824264, LP: #1581807)

 -- Benjamin Drung <email address hidden> Sat, 14 May 2016 16:39:48 +0200

[Martin Pitt (pitti)]

Please add a proper SRU test case and regression potential to the description.

[Steve Langasek (vorlon)]

Rejecting the upload from the xenial queue, still missing an SRU test case and explanation of regression potential as per comment #3. Can be reuploaded once this information is available, or you can ping a member of the SRU team when this is done to un-reject the package.

[Benjamin Drung (bdrung)]

Sorry, I missed the requests for the SRU test case and regression potential. I added them to the description and re-uploaded the package.

[Robie Basak (racb)]

Hello Benjamin, or anyone else affected,

Accepted wxwidgets3.0 into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/wxwidgets3.0/3.0.2+dfsg-1.3ubuntu0.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Benjamin Drung (bdrung)]

Ran the test case described in the description using xenial-proposed:

sbuild -d xenial --extra-repository="deb http://de.archive.ubuntu.com/ubuntu xenial-proposed main universe" audacity_$version.dsc

Build succeeded and build log says:

Setting up libwxgtk3.0-0v5:amd64 (3.0.2+dfsg-1.3ubuntu0.1) ...
Setting up wx-common (3.0.2+dfsg-1.3ubuntu0.1) ...
Setting up libwxgtk3.0-dev (3.0.2+dfsg-1.3ubuntu0.1) ...

Verification done.

[Launchpad Janitor (janitor)]

This bug was fixed in the package wxwidgets3.0 - 3.0.2+dfsg-1.3ubuntu0.1

---------------
wxwidgets3.0 (3.0.2+dfsg-1.3ubuntu0.1) xenial-proposed; urgency=medium

  * Define wxIsNaN() as std::isnan() in C++11 mode. This fixes the build
    failure of Audacity (Closes: #824264, LP: #1581807)

 -- Benjamin Drung <email address hidden> Tue, 03 Jan 2017 23:11:31 +0100

[Chris J Arges (arges)]

The verification of the Stable Release Update for wxwidgets3.0 has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.