Avoid overrunning stack at the end of the varargs.

10 jobs for fix-stack-overrun in 20 minutes and 2 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Build
passed #334903
cross-android_api21_arm64

00:01:16

passed #334904
cross-android_api28_arm64

00:03:17

passed #334905
cross-mingw64

00:01:48

passed #334901
debian-stable-x86_64

00:06:52

passed #334900
fedora-x86_64

00:08:47

passed #334902
G_DISABLE_ASSERT

00:06:51

passed #334906
win32
msys2-mingw32

00:14:02

passed #334907
win32
vs2017-x64

00:09:40

 
  Coverage
passed #334908
coverage

00:01:25

77.8%
 
  Analysis
passed #334909
scan-build

00:04:35