fixed testruns for mingw

tests/auto/testrun.pri

@@ -5,19 +5,20 @@ win32 {
 		runtarget.recurse_target = run-tests
 		QMAKE_EXTRA_TARGETS += runtarget
 	} else {
+		oneshell.target = .ONESHELL
+
+		CONFIG(debug, debug|release): outdir_helper = debug
+		CONFIG(release, debug|release): outdir_helper = release
 		runtarget.target = run-tests
 		runtarget.depends += $(DESTDIR_TARGET)
-		win32-g++ {
-			runtarget.commands += @setlocal
-			runtarget.commands += $$escape_expand(\\n\\t)@set PATH=$$shell_path($$shadowed($$dirname(_QMAKE_CONF_))/bin);$$shell_path($$[QT_INSTALL_BINS]);$(PATH)
-		} else: runtarget.commands += @set PATH=$$shell_path($$shadowed($$dirname(_QMAKE_CONF_))/bin);$$shell_path($$[QT_INSTALL_BINS]);$(PATH)
+		runtarget.commands += @set PATH=$$shell_path($$shadowed($$dirname(_QMAKE_CONF_))/bin);$$shell_path($$[QT_INSTALL_BINS]);$(PATH)
 		runtarget.commands += $$escape_expand(\\n\\t)@set QT_PLUGIN_PATH=$$shadowed($$dirname(_QMAKE_CONF_))/plugins;$(QT_PLUGIN_PATH)
 		runtarget.commands += $$escape_expand(\\n\\t)@set QML2_IMPORT_PATH=$$shadowed($$dirname(_QMAKE_CONF_))/qml;$(QML2_IMPORT_PATH)
-		runtarget.commands += $$escape_expand(\\n\\t)@set QT_QPA_PLATFORM=minimal
-		runtarget.commands += $$escape_expand(\\n\\t)start /w call $(DESTDIR_TARGET) ^> $(DESTDIR)test.log ^|^| echo FAIL ^> fail ^& exit 0
-		runtarget.commands += $$escape_expand(\\n\\t)type $(DESTDIR)test.log
-		runtarget.commands += $$escape_expand(\\n\\t)@if exist fail exit 42
-		QMAKE_EXTRA_TARGETS += runtarget
+		runtarget.commands += $$escape_expand(\\n\\t)@if exist $${outdir_helper}\\fail del $${outdir_helper}\\fail
+		runtarget.commands += $$escape_expand(\\n\\t)start /w call $(DESTDIR_TARGET) ^> $${outdir_helper}\\test.log ^|^| echo FAIL ^> $${outdir_helper}\\fail ^& exit 0
+		runtarget.commands += $$escape_expand(\\n\\t)type $${outdir_helper}\\test.log
+		runtarget.commands += $$escape_expand(\\n\\t)@if exist $${outdir_helper}\\fail exit 42
+		QMAKE_EXTRA_TARGETS += oneshell runtarget
 	}
 } else {
 	linux {