3 files changed, 26 insertions, 10 deletions
diff --git a/src/corelib/io/qprocess.cpp b/src/corelib/io/qprocess.cpp
index 0436aa5428..b03e96d0f6 100644
--- a/src/corelib/io/qprocess.cpp
+++ b/src/corelib/io/qprocess.cpp
@@ -1,6 +1,7 @@
 /****************************************************************************
 **
 ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Copyright (C) 2014 Intel Corporation
 ** Contact: http://www.qt-project.org/legal
 **
 ** This file is part of the QtCore module of the Qt Toolkit.
@@ -907,18 +908,17 @@ bool QProcessPrivate::tryReadFromChannel(Channel *channel)
         return false;
 
     qint64 available = bytesAvailableInChannel(channel);
-    if (available == 0) {
-        if (channel->notifier)
-            channel->notifier->setEnabled(false);
-        closeChannel(channel);
-#if defined QPROCESS_DEBUG
-        qDebug("QProcessPrivate::tryReadFromChannel(%d), 0 bytes available", channel - &stdinChannel);
-#endif
-        return false;
-    }
+    if (available == 0)
+        available = 1;      // always try to read at least one byte
 
     char *ptr = channel->buffer.reserve(available);
     qint64 readBytes = readFromChannel(channel, ptr, available);
+    if (readBytes <= 0)
+        channel->buffer.chop(available);
+    if (readBytes == -2) {
+        // EWOULDBLOCK
+        return false;
+    }
     if (readBytes == -1) {
         processError = QProcess::ReadError;
         q->setErrorString(QProcess::tr("Error reading from process"));
@@ -928,6 +928,16 @@ bool QProcessPrivate::tryReadFromChannel(Channel *channel)
 #endif
         return false;
     }
+    if (readBytes == 0) {
+        // EOF
+        if (channel->notifier)
+            channel->notifier->setEnabled(false);
+        closeChannel(channel);
+#if defined QPROCESS_DEBUG
+        qDebug("QProcessPrivate::tryReadFromChannel(%d), 0 bytes available", channel - &stdinChannel);
+#endif
+        return false;
+    }
 #if defined QPROCESS_DEBUG
     qDebug("QProcessPrivate::tryReadFromChannel(%d), read %d bytes from the process' output", channel - &stdinChannel
             int(readBytes));
diff --git a/src/corelib/io/qprocess_unix.cpp b/src/corelib/io/qprocess_unix.cpp
index 3c1eeb5f91..2269740a2f 100644
--- a/src/corelib/io/qprocess_unix.cpp
+++ b/src/corelib/io/qprocess_unix.cpp
@@ -981,10 +981,14 @@ qint64 QProcessPrivate::readFromChannel(const Channel *channel, char *data, qint
     Q_ASSERT(channel->pipe[0] != INVALID_Q_PIPE);
     qint64 bytesRead = qt_safe_read(channel->pipe[0], data, maxlen);
 #if defined QPROCESS_DEBUG
+    int save_errno = errno;
     qDebug("QProcessPrivate::readFromChannel(%d, %p \"%s\", %lld) == %lld",
            channel - &stdinChannel,
            data, qt_prettyDebug(data, bytesRead, 16).constData(), maxlen, bytesRead);
+    errno = save_errno;
 #endif
+    if (bytesRead == -1 && errno == EWOULDBLOCK)
+        return -2;
     return bytesRead;
 }
 
diff --git a/src/corelib/io/qwindowspipereader.cpp b/src/corelib/io/qwindowspipereader.cpp
index 7dd2125e70..d8a3ec9b42 100644
--- a/src/corelib/io/qwindowspipereader.cpp
+++ b/src/corelib/io/qwindowspipereader.cpp
@@ -132,7 +132,7 @@ qint64 QWindowsPipeReader::bytesAvailable() const
 qint64 QWindowsPipeReader::read(char *data, qint64 maxlen)
 {
     if (pipeBroken && actualReadBufferSize == 0)
-        return -1;  // signal EOF
+        return 0;  // signal EOF
 
     qint64 readSoFar;
     // If startAsyncRead() has read data, copy it to its destination.
@@ -159,6 +159,8 @@ qint64 QWindowsPipeReader::read(char *data, qint64 maxlen)
             emitReadyReadTimer->stop();
         if (!readSequenceStarted)
             startAsyncRead();
+        if (readSoFar == 0)
+            return -2;      // signal EWOULDBLOCK
     }
 
     return readSoFar;