Fixed broken logic in evdev input plugins.

If we do multiple reads we need to accumulate the total amount of bytes
read, instead of just taking the last read amount into account.

Change-Id: Iaa9b90c269f3ed9d09dae67452ca816d9db6217f
Reviewed-by: Johannes Zellner <[email protected]>
Reviewed-by: Girish Ramakrishnan <[email protected]>

3 files changed, 41 insertions, 29 deletions

diff --git a/src/plugins/generic/evdevkeyboard/qevdevkeyboardhandler.cpp b/src/plugins/generic/evdevkeyboard/qevdevkeyboardhandler.cpp
index 73aa6419d36..eb29b853e78 100644
--- a/src/plugins/generic/evdevkeyboard/qevdevkeyboardhandler.cpp
+++ b/src/plugins/generic/evdevkeyboard/qevdevkeyboardhandler.cpp
@@ -168,16 +168,20 @@ void QEvdevKeyboardHandler::readKeycode()
     int n = 0;
 
     forever {
-        n = qt_safe_read(m_fd, reinterpret_cast<char *>(buffer) + n, sizeof(buffer) - n);
+        int result = qt_safe_read(m_fd, reinterpret_cast<char *>(buffer) + n, sizeof(buffer) - n);
 
-        if (n == 0) {
+        if (result == 0) {
             qWarning("Got EOF from the input device.");
             return;
-        } else if (n < 0 && (errno != EINTR && errno != EAGAIN)) {
-           qWarning("Could not read from input device: %s", strerror(errno));
-            return;
-        } else if (n % sizeof(buffer[0]) == 0) {
-            break;
+        } else if (result < 0) {
+            if (errno != EINTR && errno != EAGAIN) {
+                qWarning("Could not read from input device: %s", strerror(errno));
+                return;
+            }
+        } else {
+            n += result;
+            if (n % sizeof(buffer[0]) == 0)
+                break;
         }
     }
 
diff --git a/src/plugins/generic/evdevmouse/qevdevmousehandler.cpp b/src/plugins/generic/evdevmouse/qevdevmousehandler.cpp
index 7c05e9ff114..5e2911a806e 100644
--- a/src/plugins/generic/evdevmouse/qevdevmousehandler.cpp
+++ b/src/plugins/generic/evdevmouse/qevdevmousehandler.cpp
@@ -145,16 +145,20 @@ void QEvdevMouseHandler::readMouseData()
     bool pendingMouseEvent = false;
     int eventCompressCount = 0;
     forever {
-        n = QT_READ(m_fd, reinterpret_cast<char *>(buffer) + n, sizeof(buffer) - n);
+        int result = QT_READ(m_fd, reinterpret_cast<char *>(buffer) + n, sizeof(buffer) - n);
 
-        if (n == 0) {
+        if (result == 0) {
             qWarning("Got EOF from the input device.");
             return;
-        } else if (n < 0 && (errno != EINTR && errno != EAGAIN)) {
-            qWarning("Could not read from input device: %s", strerror(errno));
-            return;
-        } else if (n % sizeof(buffer[0]) == 0) {
-            break;
+        } else if (result < 0) {
+            if (errno != EINTR && errno != EAGAIN) {
+                qWarning("Could not read from input device: %s", strerror(errno));
+                return;
+            }
+        } else {
+            n += result;
+            if (n % sizeof(buffer[0]) == 0)
+                break;
         }
     }
 
diff --git a/src/plugins/generic/evdevtouch/qevdevtouch.cpp b/src/plugins/generic/evdevtouch/qevdevtouch.cpp
index c9c49839d64..1c3e8952e96 100644
--- a/src/plugins/generic/evdevtouch/qevdevtouch.cpp
+++ b/src/plugins/generic/evdevtouch/qevdevtouch.cpp
@@ -253,26 +253,30 @@ void QTouchScreenHandler::readData()
     int n = 0;
     for (; ;) {
 #ifdef USE_MTDEV
-        n = mtdev_get(m_mtdev, m_fd, buffer, sizeof(buffer) / sizeof(::input_event));
-        if (n > 0)
-            n *= sizeof(::input_event);
+        int result = mtdev_get(m_mtdev, m_fd, buffer, sizeof(buffer) / sizeof(::input_event));
+        if (result > 0)
+            result *= sizeof(::input_event);
 #else
-        n = QT_READ(m_fd, reinterpret_cast<char*>(buffer) + n, sizeof(buffer) - n);
+        int result = QT_READ(m_fd, reinterpret_cast<char*>(buffer) + n, sizeof(buffer) - n);
 #endif
-        if (!n) {
+        if (!result) {
             qWarning("Got EOF from input device");
             return;
-        } else if (n < 0 && (errno != EINTR && errno != EAGAIN)) {
-            qWarning("Could not read from input device: %s", strerror(errno));
-            if (errno == ENODEV) { // device got disconnected -> stop reading
-                delete m_notify;
-                m_notify = 0;
-                QT_CLOSE(m_fd);
-                m_fd = -1;
+        } else if (result < 0) {
+            if (errno != EINTR && errno != EAGAIN) {
+                qWarning("Could not read from input device: %s", strerror(errno));
+                if (errno == ENODEV) { // device got disconnected -> stop reading
+                    delete m_notify;
+                    m_notify = 0;
+                    QT_CLOSE(m_fd);
+                    m_fd = -1;
+                }
+                return;
             }
-            return;
-        } else if (n % sizeof(::input_event) == 0) {
-            break;
+        } else {
+            n += result;
+            if (n % sizeof(::input_event) == 0)
+                break;
         }
     }