This commit adds those three flags that are either frequent enough or
difficult to do: close all file descriptors above stderr and reset the
signal handlers. Setting SIGPIPE to be ignored isn't critical, but is
required when the ResetSignalHandlers flag is used, as this is run
after the user child process modifier.
[ChangeLog][QtCore][QProcess] Added setUnixProcessParameters() function
that can be used to modify certain settings of the child process,
without the need to provide a callback using setChildProcessModifier().
Change-Id: Icfe44ecf285a480fafe4fffd174d0d1d63840403
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
f9c87cfd44