QProcess: Ensure that the stdin buffer is cleared on start()

The buffer may have been left dirty if we were unable to write all the
data to the child process in the previous run. So ensure we clear it
before starting a new one. We already did that for stdout and stderr,
for some reason.

Task-number: QTBUG-44517
Change-Id: I1a800c709d3543699131ffff13c419da3bbffacf
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/tests/auto/corelib/io/qprocess/testProcessHang/testProcessHang.pro b/tests/auto/corelib/io/qprocess/testProcessHang/testProcessHang.pro
new file mode 100644
index 0000000000..e236e05c7d
--- /dev/null
+++ b/tests/auto/corelib/io/qprocess/testProcessHang/testProcessHang.pro
@@ -0,0 +1,4 @@
+SOURCES = main.cpp
+CONFIG -= qt app_bundle
+CONFIG += console
+DESTDIR = ./