Fix Modbus custom command response processing

QModbusClient:
 Checking for QModbusReply::Common will suppress calling into the
 existing and supposed to be called QModbusClient::processPrivateRequest
 function, which is to only way to handle a response from a raw request.

QModbusReply:
 There was probably a workaround used since the QModbusReply does expose
 the response and in case of QModbusReply::Raw the API user could still
 get the reply and work their way through. Now you can get the result back,
 proccessed by QModbusClient::processPrivateRequest if the user implements
 it. The function behavior does not change, as in any case except the
 QModbusReply::Common the the returned unit was invalid anyways.

[ChangeLog] Fix Modbus custom command response processing.

Task-number: QTBUG-91214
Change-Id: I09beeef9f236a29ffc0abf4b3dd323c9ce8ba1a4
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>
(cherry picked from commit 09927894825d97197ffa656576e6be780371dda0)

2 files changed, 7 insertions, 5 deletions

diff --git a/src/serialbus/qmodbusclient.cpp b/src/serialbus/qmodbusclient.cpp
index 768a59d..a4840f6 100644
--- a/src/serialbus/qmodbusclient.cpp
+++ b/src/serialbus/qmodbusclient.cpp
@@ -361,7 +361,7 @@ void QModbusClientPrivate::processQueueElement(const QModbusResponse &pdu,
         return;
     }
 
-    if (element.reply->type() != QModbusReply::Common) {
+    if (element.reply->type() == QModbusReply::Broadcast) {
         element.reply->setFinished(true);
         return;
     }
diff --git a/src/serialbus/qmodbusreply.cpp b/src/serialbus/qmodbusreply.cpp
index 771d14c..ca65aac 100644
--- a/src/serialbus/qmodbusreply.cpp
+++ b/src/serialbus/qmodbusreply.cpp
@@ -147,15 +147,17 @@ void QModbusReply::setFinished(bool isFinished)
     If the request has not finished, has failed with an error or was a write
     request then the returned \l QModbusDataUnit instance is invalid.
 
-    \note If the \l type() of the reply is \l QModbusReply::Raw, the return
-    value will always be invalid.
+    \note If the \l type() of the reply is \l QModbusReply::Broadcast, the
+    return value will always be invalid. If the l type() of the reply is
+    \l QModbusReply::Raw, the return value might be invalid depending on the
+    implementation of \l QModbusClient::processPrivateResponse().
 
-    \sa type(), rawResult()
+    \sa type(), rawResult(), QModbusClient::processPrivateResponse()
 */
 QModbusDataUnit QModbusReply::result() const
 {
     Q_D(const QModbusReply);
-    if (type() == QModbusReply::Common)
+    if (type() != QModbusReply::Broadcast)
         return d->m_unit;
     return QModbusDataUnit();
 }