Fix crash when callbacks have out arguments

https://bugzilla.gnome.org/show_bug.cgi?id=729082
12 jobs for wip/xclaesse/729082-crash-when-callbacks-vfuncs-have-out-arguments in 7 minutes and 16 seconds (queued for 55 seconds)
latest
Status Name Job ID Coverage
  Source Check
passed cppcheck #31330

00:01:59

passed cpplint #31331

00:02:30

passed eslint #31332

00:02:08

failed fedora #31329

00:07:16

 
  Test
skipped fedora_clang #31333
 
  Thorough Tests
skipped installed_tests #31335
skipped lts #31339
allowed to fail manual
skipped no_graphics #31338
allowed to fail manual
skipped no_profiler #31334
skipped sanitizer_gcc #31336
skipped valgrind #31337
allowed to fail manual
 
  Delivery
skipped packaging #31340
allowed to fail manual
 
Name Stage Failure
failed
fedora Source Check
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