Fix logic with the wrong priority of operations

The assignment '=' operator has a lower priority,
than the comparison '==, !=' operators. Thus, the
result of logical statements is wrong.

Change-Id: Iab281f1f3dd95b59da94379fd68a45f75e2dd5ac
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
Reviewed-by: André Hartmann <aha_1980@gmx.de>
Reviewed-by: Alex Blasche <alexander.blasche@theqtcompany.com>

1 files changed, 30 insertions, 16 deletions

diff --git a/src/plugins/canbus/tinycan/tinycanbackend.cpp b/src/plugins/canbus/tinycan/tinycanbackend.cpp
index 530959a..b86e5f9 100644
--- a/src/plugins/canbus/tinycan/tinycanbackend.cpp
+++ b/src/plugins/canbus/tinycan/tinycanbackend.cpp
@@ -170,21 +170,30 @@ bool TinyCanBackendPrivate::open()
 {
     Q_Q(TinyCanBackend);
 
-    char options[] = "AutoConnect=1;AutoReopen=0";
-    if (int ret = ::CanSetOptions(options) < 0) {
-        q->setError(systemErrorString(ret), QCanBusDevice::CanBusError::ConnectionError);
-        return false;
+    {
+        char options[] = "AutoConnect=1;AutoReopen=0";
+        const int ret = ::CanSetOptions(options);
+        if (ret < 0) {
+            q->setError(systemErrorString(ret), QCanBusDevice::CanBusError::ConnectionError);
+            return false;
+        }
     }
 
-    if (int ret = ::CanDeviceOpen(channelIndex, nullptr) < 0) {
-        q->setError(systemErrorString(ret), QCanBusDevice::CanBusError::ConnectionError);
-        return false;
+    {
+        const int ret = ::CanDeviceOpen(channelIndex, nullptr);
+        if (ret < 0) {
+            q->setError(systemErrorString(ret), QCanBusDevice::CanBusError::ConnectionError);
+            return false;
+        }
     }
 
-    if (int ret = ::CanSetMode(channelIndex, OP_CAN_START, CAN_CMD_ALL_CLEAR) < 0) {
-        q->setError(systemErrorString(ret), QCanBusDevice::CanBusError::ConnectionError);
-        ::CanDeviceClose(channelIndex);
-        return false;
+    {
+        const int ret = ::CanSetMode(channelIndex, OP_CAN_START, CAN_CMD_ALL_CLEAR);
+        if (ret < 0) {
+            q->setError(systemErrorString(ret), QCanBusDevice::CanBusError::ConnectionError);
+            ::CanDeviceClose(channelIndex);
+            return false;
+        }
     }
 
     isOpen = true;
@@ -195,7 +204,8 @@ void TinyCanBackendPrivate::close()
 {
     Q_Q(TinyCanBackend);
 
-    if (int ret = ::CanDeviceClose(channelIndex) < 0)
+    const int ret = ::CanDeviceClose(channelIndex);
+    if (ret < 0)
         q->setError(systemErrorString(ret), QCanBusDevice::CanBusError::ConnectionError);
 
     isOpen = false;
@@ -353,7 +363,8 @@ void TinyCanBackendPrivate::canWriteNotification()
 
         const qint32 messagesToWrite = 1;
         ::memcpy(message.Data.Bytes, payload.constData(), sizeof(message.Data.Bytes));
-        if (int ret = ::CanTransmit(channelIndex, &message, messagesToWrite) < 0)
+        const int ret = ::CanTransmit(channelIndex, &message, messagesToWrite);
+        if (ret < 0)
             q->setError(systemErrorString(ret), QCanBusDevice::CanBusError::WriteError);
         else
             emit q->framesWritten(messagesToWrite);
@@ -386,7 +397,8 @@ void TinyCanBackendPrivate::canReadNotification()
         ::memset(&message, 0, sizeof(message));
 
         const int messagesToRead = 1;
-        if (int ret = ::CanReceive(channelIndex, &message, messagesToRead) < 0) {
+        const int ret = ::CanReceive(channelIndex, &message, messagesToRead);
+        if (ret < 0) {
             q->setError(systemErrorString(ret), QCanBusDevice::CanBusError::ReadError);
 
             TDeviceStatus status;
@@ -428,7 +440,8 @@ void TinyCanBackendPrivate::startupDriver()
     Q_Q(TinyCanBackend);
 
     if (driverRefCount == 0) {
-        if (int ret = ::CanInitDriver(nullptr) < 0) {
+        const int ret = ::CanInitDriver(nullptr);
+        if (ret < 0) {
             q->setError(systemErrorString(ret), QCanBusDevice::CanBusError::ConnectionError);
             return;
         }
@@ -468,7 +481,8 @@ bool TinyCanBackendPrivate::setBitRate(int bitrate)
     }
 
     if (isOpen) {
-        if (int ret = ::CanSetSpeed(channelIndex, bitrateCode) < 0) {
+        const int ret = ::CanSetSpeed(channelIndex, bitrateCode);
+        if (ret < 0) {
             q->setError(systemErrorString(ret), QCanBusDevice::CanBusError::ConfigurationError);
             return false;
         }