diff --git a/src/corelib/io/qprocess.cpp b/src/corelib/io/qprocess.cpp
index 095847122a..9c6dafd7ef 100644
--- a/src/corelib/io/qprocess.cpp
+++ b/src/corelib/io/qprocess.cpp
@@ -940,6 +940,78 @@ void QProcessPrivate::setErrorAndEmit(QProcess::ProcessError error, const QStrin
     emit q->errorOccurred(processError);
 }
 
+/*!
+    \internal
+*/
+bool QProcessPrivate::openChannels()
+{
+    // stdin channel.
+    if (inputChannelMode == QProcess::ForwardedInputChannel) {
+        if (stdinChannel.type != Channel::Normal)
+            qWarning("QProcess::openChannels: Inconsistent stdin channel configuration");
+    } else if (!openChannel(stdinChannel)) {
+        return false;
+    }
+
+    // stdout channel.
+    if (processChannelMode == QProcess::ForwardedChannels
+            || processChannelMode == QProcess::ForwardedOutputChannel) {
+        if (stdoutChannel.type != Channel::Normal)
+            qWarning("QProcess::openChannels: Inconsistent stdout channel configuration");
+    } else if (!openChannel(stdoutChannel)) {
+        return false;
+    }
+
+    // stderr channel.
+    if (processChannelMode == QProcess::ForwardedChannels
+            || processChannelMode == QProcess::ForwardedErrorChannel
+            || processChannelMode == QProcess::MergedChannels) {
+        if (stderrChannel.type != Channel::Normal)
+            qWarning("QProcess::openChannels: Inconsistent stderr channel configuration");
+    } else if (!openChannel(stderrChannel)) {
+        return false;
+    }
+
+    return true;
+}
+
+/*!
+    \internal
+*/
+bool QProcessPrivate::openChannelsForDetached()
+{
+    // stdin channel.
+    if (stdinChannel.type != Channel::Normal
+            && (stdinChannel.type != Channel::Redirect
+                || inputChannelMode == QProcess::ForwardedInputChannel)) {
+        qWarning("QProcess::openChannelsForDetached: Inconsistent stdin channel configuration");
+    }
+    if (stdinChannel.type == Channel::Redirect && !openChannel(stdinChannel))
+        return false;
+
+    // stdout channel.
+    if (stdoutChannel.type != Channel::Normal
+            && (stdoutChannel.type != Channel::Redirect
+                || processChannelMode == QProcess::ForwardedChannels
+                || processChannelMode == QProcess::ForwardedOutputChannel)) {
+        qWarning("QProcess::openChannelsForDetached: Inconsistent stdout channel configuration");
+    }
+    if (stdoutChannel.type == Channel::Redirect && !openChannel(stdoutChannel))
+        return false;
+
+    // stderr channel.
+    if (processChannelMode == QProcess::MergedChannels || (stderrChannel.type != Channel::Normal
+            && (stderrChannel.type != Channel::Redirect
+                || processChannelMode == QProcess::ForwardedChannels
+                || processChannelMode == QProcess::ForwardedErrorChannel))) {
+        qWarning("QProcess::openChannelsForDetached: Inconsistent stderr channel configuration");
+    }
+    if (stderrChannel.type == Channel::Redirect && !openChannel(stderrChannel))
+        return false;
+
+    return true;
+}
+
 /*!
     \internal
     Returns \c true if we emitted readyRead().
diff --git a/src/corelib/io/qprocess_p.h b/src/corelib/io/qprocess_p.h
index 023d69e8d5..3be73f479e 100644
--- a/src/corelib/io/qprocess_p.h
+++ b/src/corelib/io/qprocess_p.h
@@ -316,6 +316,8 @@ public:
     Channel stdinChannel;
     Channel stdoutChannel;
     Channel stderrChannel;
+    bool openChannels();
+    bool openChannelsForDetached();
     bool openChannel(Channel &channel);
     void closeChannel(Channel *channel);
     void closeWriteChannel();
diff --git a/src/corelib/io/qprocess_unix.cpp b/src/corelib/io/qprocess_unix.cpp
index 07d427047d..f12d92b253 100644
--- a/src/corelib/io/qprocess_unix.cpp
+++ b/src/corelib/io/qprocess_unix.cpp
@@ -221,36 +221,11 @@ void QProcessPrivate::closeChannel(Channel *channel)
 
 /*
     Create the pipes to a QProcessPrivate::Channel.
-
-    This function must be called in order: stdin, stdout, stderr
 */
 bool QProcessPrivate::openChannel(Channel &channel)
 {
     Q_Q(QProcess);
 
-    // Handle forwarding of the process channels.
-    if (&channel == &stdinChannel) {
-        if (inputChannelMode == QProcess::ForwardedInputChannel)
-            return true;
-    } else {
-        switch (processChannelMode) {
-        case QProcess::ForwardedChannels:
-            return true;
-        case QProcess::ForwardedOutputChannel:
-            if (&channel == &stdoutChannel)
-                return true;
-            break;
-        case QProcess::ForwardedErrorChannel:
-        case QProcess::MergedChannels:
-            if (&channel == &stderrChannel)
-                return true;
-            break;
-        default:
-            break;
-        }
-    }
-
-    // Create pipes and handle redirections.
     if (channel.type == Channel::Normal) {
         // we're piping this channel to our own process
         if (qt_create_pipe(channel.pipe) != 0)
@@ -378,10 +353,7 @@ void QProcessPrivate::startProcess()
 #endif
 
     // Initialize pipes
-    if (!openChannel(stdinChannel) ||
-        !openChannel(stdoutChannel) ||
-        !openChannel(stderrChannel) ||
-        qt_create_pipe(childStartedPipe) != 0) {
+    if (!openChannels() || qt_create_pipe(childStartedPipe) != 0) {
         setErrorAndEmit(QProcess::FailedToStart, qt_error_string(errno));
         cleanup();
         return;
@@ -902,9 +874,7 @@ bool QProcessPrivate::startDetached(qint64 *pid)
         return false;
     }
 
-    if ((stdinChannel.type == Channel::Redirect && !openChannel(stdinChannel))
-            || (stdoutChannel.type == Channel::Redirect && !openChannel(stdoutChannel))
-            || (stderrChannel.type == Channel::Redirect && !openChannel(stderrChannel))) {
+    if (!openChannelsForDetached()) {
         closeChannel(&stdinChannel);
         closeChannel(&stdoutChannel);
         closeChannel(&stderrChannel);
diff --git a/src/corelib/io/qprocess_win.cpp b/src/corelib/io/qprocess_win.cpp
index 886c4e8587..c9223443e2 100644
--- a/src/corelib/io/qprocess_win.cpp
+++ b/src/corelib/io/qprocess_win.cpp
@@ -180,40 +180,23 @@ static bool qt_create_pipe(Q_PIPE *pipe, bool isInputPipe)
 
 /*
     Create the pipes to a QProcessPrivate::Channel.
-
-    This function must be called in order: stdin, stdout, stderr
 */
 bool QProcessPrivate::openChannel(Channel &channel)
 {
     Q_Q(QProcess);
 
-    if (&channel == &stderrChannel && processChannelMode == QProcess::MergedChannels)
-        return true;
-
     switch (channel.type) {
     case Channel::Normal: {
         // we're piping this channel to our own process
-        if (&channel == &stdinChannel) {
-            return inputChannelMode == QProcess::ForwardedInputChannel
-                   || qt_create_pipe(channel.pipe, true);
-        }
+        if (&channel == &stdinChannel)
+            return qt_create_pipe(channel.pipe, true);
 
         if (&channel == &stdoutChannel) {
-            if (processChannelMode == QProcess::ForwardedChannels
-                    || processChannelMode == QProcess::ForwardedOutputChannel) {
-                return true;
-            }
-
             if (!stdoutChannel.reader) {
                 stdoutChannel.reader = new QWindowsPipeReader(q);
                 q->connect(stdoutChannel.reader, SIGNAL(readyRead()), SLOT(_q_canReadStandardOutput()));
             }
         } else /* if (&channel == &stderrChannel) */ {
-            if (processChannelMode == QProcess::ForwardedChannels
-                    || processChannelMode == QProcess::ForwardedErrorChannel) {
-                return true;
-            }
-
             if (!stderrChannel.reader) {
                 stderrChannel.reader = new QWindowsPipeReader(q);
                 q->connect(stderrChannel.reader, SIGNAL(readyRead()), SLOT(_q_canReadStandardError()));
@@ -545,9 +528,7 @@ void QProcessPrivate::startProcess()
 
     q->setProcessState(QProcess::Starting);
 
-    if (!openChannel(stdinChannel) ||
-        !openChannel(stdoutChannel) ||
-        !openChannel(stderrChannel)) {
+    if (!openChannels()) {
         QString errorString = QProcess::tr("Process failed to start: %1").arg(qt_error_string());
         cleanup();
         setErrorAndEmit(QProcess::FailedToStart, errorString);
@@ -913,9 +894,7 @@ bool QProcessPrivate::startDetached(qint64 *pid)
 {
     static const DWORD errorElevationRequired = 740;
 
-    if ((stdinChannel.type == Channel::Redirect && !openChannel(stdinChannel))
-            || (stdoutChannel.type == Channel::Redirect && !openChannel(stdoutChannel))
-            || (stderrChannel.type == Channel::Redirect && !openChannel(stderrChannel))) {
+    if (!openChannelsForDetached()) {
         closeChannel(&stdinChannel);
         closeChannel(&stdoutChannel);
         closeChannel(&stderrChannel);