Suppress error emission when closing

When the error signal is connected to a slot which calls QSP::close()
and an error occurs in this method, this would lead to infinite recursion.
Other Qt I/O classes avoid this problem by not emitting errors while
closing the device, so we should not, either.

Task-number: QTBUG-50052
Change-Id: Icfbcb19c32b8bd7fc586ab5253dc754e78829f11
Reviewed-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>

2 files changed, 8 insertions, 17 deletions

diff --git a/src/serialport/qserialport_unix.cpp b/src/serialport/qserialport_unix.cpp
index 960349e..7153449 100644
--- a/src/serialport/qserialport_unix.cpp
+++ b/src/serialport/qserialport_unix.cpp
@@ -237,14 +237,11 @@ bool QSerialPortPrivate::open(QIODevice::OpenMode mode)
 
 void QSerialPortPrivate::close()
 {
-    if (settingsRestoredOnClose) {
-        if (::tcsetattr(descriptor, TCSANOW, &restoredTermios) == -1)
-            setError(getSystemError());
-    }
+    if (settingsRestoredOnClose)
+        ::tcsetattr(descriptor, TCSANOW, &restoredTermios);
 
 #ifdef TIOCNXCL
-    if (::ioctl(descriptor, TIOCNXCL) == -1)
-        setError(getSystemError());
+    ::ioctl(descriptor, TIOCNXCL);
 #endif
 
     if (readNotifier) {
@@ -257,8 +254,7 @@ void QSerialPortPrivate::close()
         writeNotifier = Q_NULLPTR;
     }
 
-    if (qt_safe_close(descriptor) == -1)
-        setError(getSystemError());
+    qt_safe_close(descriptor);
 
     lockFileScopedPointer.reset(Q_NULLPTR);
 
diff --git a/src/serialport/qserialport_win.cpp b/src/serialport/qserialport_win.cpp
index 6e1a44f..f176025 100644
--- a/src/serialport/qserialport_win.cpp
+++ b/src/serialport/qserialport_win.cpp
@@ -104,8 +104,7 @@ bool QSerialPortPrivate::open(QIODevice::OpenMode mode)
 
 void QSerialPortPrivate::close()
 {
-    if (!::CancelIo(handle))
-        setError(getSystemError());
+    ::CancelIo(handle);
 
     if (notifier) {
         delete notifier;
@@ -124,15 +123,11 @@ void QSerialPortPrivate::close()
     actualBytesToWrite = 0;
 
     if (settingsRestoredOnClose) {
-        if (!::SetCommState(handle, &restoredDcb))
-            setError(getSystemError());
-        else if (!::SetCommTimeouts(handle, &restoredCommTimeouts))
-            setError(getSystemError());
+        ::SetCommState(handle, &restoredDcb);
+        ::SetCommTimeouts(handle, &restoredCommTimeouts);
     }
 
-    if (!::CloseHandle(handle))
-        setError(getSystemError());
-
+    ::CloseHandle(handle);
     handle = INVALID_HANDLE_VALUE;
 }