Fix failure to report DBUS non-fatal errors

tqdbusconnection.cpp

@@ -290,14 +290,9 @@ TQT_DBusMessage TQT_DBusConnection::sendWithReply(const TQT_DBusMessage &message
 
     TQT_DBusMessage ret = TQT_DBusMessage::fromDBusMessage(reply);
 
-    // HACK
-    // Reset the error object if no error was reported by DBus
-    // This is needed because TQT_DBusMessage::fromDBusMessage sometimes sets the error object even if DBus did not report a fatal error,
-    // and the dbus_error_is_set() check cannot be moved inside fromDBusMessage() without breaking the API and ABI.
-    if (!dbus_error_is_set(&d->error)) {
-        ret.d->error = TQT_DBusError();
-        if (error) *error = TQT_DBusError();
-    }
+    bool dbus_error_set = dbus_error_is_set(&d->error);
+    ret.d->error.setDBUSError(dbus_error_set);
+    if (error) error->setDBUSError(dbus_error_set);
 
     return ret;
 }

tqdbuserror.cpp

@@ -113,11 +113,11 @@ static TQT_DBusError::ErrorType qDBusErrorTypeForName(const TQString& name)
     return TQT_DBusError::UserDefined;
 }
 
-TQT_DBusError::TQT_DBusError() : errorType(InvalidError)
+TQT_DBusError::TQT_DBusError() : errorType(InvalidError), m_dbusErrorSet(false)
 {
 }
 
-TQT_DBusError::TQT_DBusError(const DBusError *error) : errorType(InvalidError)
+TQT_DBusError::TQT_DBusError(const DBusError *error) : errorType(InvalidError), m_dbusErrorSet(false)
 {
     if (!error || !dbus_error_is_set(error))
         return;
@@ -129,7 +129,7 @@ TQT_DBusError::TQT_DBusError(const DBusError *error) : errorType(InvalidError)
 }
 
 TQT_DBusError::TQT_DBusError(const TQString& error, const TQString& message)
-    : errorType(UserDefined), nm(error), msg(message)
+    : errorType(UserDefined), m_dbusErrorSet(false), nm(error), msg(message)
 {
     errorType = qDBusErrorTypeForName(nm);
 }
@@ -140,7 +140,7 @@ bool TQT_DBusError::isValid() const
 }
 
 TQT_DBusError::TQT_DBusError(ErrorType type, const TQString& message)
-    : errorType(type), msg(message)
+    : errorType(type), m_dbusErrorSet(false), msg(message)
 {
     nm = qDBusErrorNameForType(type);
 }

tqdbuserror.h

@@ -306,6 +306,20 @@ public:
      */
     inline ErrorType type() const { return errorType; }
 
+    /**
+     * @brief Returns whether the error was caused by DBUS itself
+     *
+     * A TQT_DBusError is considered valid if both name and message are set.
+     *
+     * @return @c true if dbus_error_is_set was true after DBUS call completion
+     */
+    inline bool dbusErrorSet() const { return m_dbusErrorSet; }
+
+    /**
+     * @internal
+     */
+    inline void setDBUSError(bool err) const { m_dbusErrorSet = err; }
+
     /**
      * @brief Returns whether the error object is valid
      *
@@ -444,6 +458,7 @@ public:
 
 private:
     ErrorType errorType;
+    mutable bool m_dbusErrorSet;
 
     TQString nm, msg;