Spurious warning: ‘r’ may be used uninitialized in this function [-Wmaybe-uninitialized]

[Daniel van Vugt]

gcc is giving an apparently spurious warning:

shadow.c: In function ‘create_shadowed_pixbuf’:
shadow.c:16:28: warning: ‘r’ may be used uninitialized in this function [-Wmaybe-uninitialized]
     return ((1 / (2 * M_PI * r)) *
                  ~~~~~~~~~~^~~~
shadow.c:14:1: note: ‘r’ was declared here
 gaussian (double x, double y, double r)
 ^~~~~~~~

It looks like that's impossible to me. The relevant source file is:

https://git.gnome.org/browse/gtk+/tree/docs/tools/shadow.c?h=gtk-3-22

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: gcc-7 7.2.0-3ubuntu1
ProcVersionSignature: Ubuntu 4.12.0-13.14-generic 4.12.10
Uname: Linux 4.12.0-13-generic x86_64
ApportVersion: 2.20.7-0ubuntu1
Architecture: amd64
Date: Fri Sep 15 14:06:45 2017
InstallationDate: Installed on 2017-05-03 (135 days ago)
InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Alpha amd64 (20170502)
SourcePackage: gcc-7
UpgradeStatus: No upgrade log present (probably fresh install)

[Daniel van Vugt (vanvugt)]

Seems to be a recurring problem:

https://gcc.gnu.org/bugzilla/buglist.cgi?quicksearch=may%20be%20used%20uninitialized