Fix 'out of process' autotests

We are, arguably, not testing QProcess and its ability to start or finish,
we test QUdpSocket. If, for some reason (as we discovered on some
specific machines recently) the process does not start or does not produce
any output (canReadLine), we QSKIP instead of failing. Also, all those
QCOMPARE will bypass the part there we stop processes - so must be
RAII-protected.

Fixes: QTBUG-82717
Change-Id: Idfb0d4a483d753f336b3827875eeaf51c79270e2
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

tests/auto/network/socket/qudpsocket/tst_qudpsocket.cpp

@@ -1090,12 +1090,21 @@ void tst_QUdpSocket::outOfProcessConnectedClientServerTest()
     QProcess serverProcess;
     serverProcess.start(QLatin1String("clientserver/clientserver server 1 1"),
                         QIODevice::ReadWrite | QIODevice::Text);
-    QVERIFY2(serverProcess.waitForStarted(3000),
+
-             qPrintable("Failed to start subprocess: " + serverProcess.errorString()));
+    const auto serverProcessCleaner = qScopeGuard([&serverProcess] {
+        serverProcess.kill();
+        serverProcess.waitForFinished();
+    });
+
+    if (!serverProcess.waitForStarted(3000))
+        QSKIP("Failed to start server as a subprocess");
 
     // Wait until the server has started and reports success.
-    while (!serverProcess.canReadLine())
+    while (!serverProcess.canReadLine()) {
-        QVERIFY(serverProcess.waitForReadyRead(3000));
+       if (!serverProcess.waitForReadyRead(3000))
+           QSKIP("No output from the server process, bailing out");
+    }
+
     QByteArray serverGreeting = serverProcess.readLine();
     QVERIFY(serverGreeting != QByteArray("XXX\n"));
     int serverPort = serverGreeting.trimmed().toInt();
@@ -1105,12 +1114,21 @@ void tst_QUdpSocket::outOfProcessConnectedClientServerTest()
     clientProcess.start(QString::fromLatin1("clientserver/clientserver connectedclient %1 %2")
                         .arg(QLatin1String("127.0.0.1")).arg(serverPort),
                         QIODevice::ReadWrite | QIODevice::Text);
-    QVERIFY2(clientProcess.waitForStarted(3000),
-             qPrintable("Failed to start subprocess: " + clientProcess.errorString()));
 
-    // Wait until the server has started and reports success.
+    const auto clientProcessCleaner = qScopeGuard([&clientProcess] {
-    while (!clientProcess.canReadLine())
+        clientProcess.kill();
-        QVERIFY(clientProcess.waitForReadyRead(3000));
+        clientProcess.waitForFinished();
+    });
+
+    if (!clientProcess.waitForStarted(3000))
+        QSKIP("Client process did not start");
+
+    // Wait until the client has started and reports success.
+    while (!clientProcess.canReadLine()) {
+        if (!clientProcess.waitForReadyRead(3000))
+            QSKIP("No output from the client process, bailing out");
+    }
+
     QByteArray clientGreeting = clientProcess.readLine();
     QCOMPARE(clientGreeting, QByteArray("ok\n"));
 
@@ -1135,11 +1153,6 @@ void tst_QUdpSocket::outOfProcessConnectedClientServerTest()
         QCOMPARE(serverData.at(i * 3 + 2).trimmed().mid(8).toInt(),
                  sdata.mid(4).trimmed().toInt() * 2);
     }
-
-    clientProcess.kill();
-    QVERIFY(clientProcess.waitForFinished());
-    serverProcess.kill();
-    QVERIFY(serverProcess.waitForFinished());
 #endif
 }
 
@@ -1151,12 +1164,21 @@ void tst_QUdpSocket::outOfProcessUnconnectedClientServerTest()
     QProcess serverProcess;
     serverProcess.start(QLatin1String("clientserver/clientserver server 1 1"),
                         QIODevice::ReadWrite | QIODevice::Text);
-    QVERIFY2(serverProcess.waitForStarted(3000),
+
-             qPrintable("Failed to start subprocess: " + serverProcess.errorString()));
+    const auto serverProcessCleaner = qScopeGuard([&serverProcess] {
+        serverProcess.kill();
+        serverProcess.waitForFinished();
+    });
+
+    if (!serverProcess.waitForStarted(3000))
+        QSKIP("Failed to start the server subprocess");
 
     // Wait until the server has started and reports success.
-    while (!serverProcess.canReadLine())
+    while (!serverProcess.canReadLine()) {
-        QVERIFY(serverProcess.waitForReadyRead(3000));
+        if (!serverProcess.waitForReadyRead(3000))
+            QSKIP("No output from the server, probably, it is not running");
+    }
+
     QByteArray serverGreeting = serverProcess.readLine();
     QVERIFY(serverGreeting != QByteArray("XXX\n"));
     int serverPort = serverGreeting.trimmed().toInt();
@@ -1166,12 +1188,21 @@ void tst_QUdpSocket::outOfProcessUnconnectedClientServerTest()
     clientProcess.start(QString::fromLatin1("clientserver/clientserver unconnectedclient %1 %2")
                         .arg(QLatin1String("127.0.0.1")).arg(serverPort),
                         QIODevice::ReadWrite | QIODevice::Text);
-    QVERIFY2(clientProcess.waitForStarted(3000),
-             qPrintable("Failed to start subprocess: " + clientProcess.errorString()));
 
-    // Wait until the server has started and reports success.
+    const auto clientProcessCleaner = qScopeGuard([&clientProcess] {
-    while (!clientProcess.canReadLine())
+        clientProcess.kill();
-        QVERIFY(clientProcess.waitForReadyRead(3000));
+        clientProcess.waitForFinished();
+    });
+
+    if (!clientProcess.waitForStarted(3000))
+        QSKIP("Failed to start the client's subprocess");
+
+    // Wait until the client has started and reports success.
+    while (!clientProcess.canReadLine()) {
+        if (!clientProcess.waitForReadyRead(3000))
+            QSKIP("The client subprocess produced not output, exiting.");
+    }
+
     QByteArray clientGreeting = clientProcess.readLine();
     QCOMPARE(clientGreeting, QByteArray("ok\n"));
 
@@ -1197,11 +1228,6 @@ void tst_QUdpSocket::outOfProcessUnconnectedClientServerTest()
         QCOMPARE(serverData.at(i * 3 + 2).trimmed().mid(8).toInt(),
                  sdata.mid(4).trimmed().toInt() * 2);
     }
-
-    clientProcess.kill();
-    QVERIFY(clientProcess.waitForFinished());
-    serverProcess.kill();
-    QVERIFY(serverProcess.waitForFinished());
 #endif
 }