Move processOpenModeFlags out of QFSFileEngine

The same logic is needed for QWinRTFileEngine. To be able to reuse the
code, it was moved out of the class.

Task-number: QTBUG-77095
Change-Id: If52b2fc8a0f3056d32fc693775565a1c3803b7d4
Reviewed-by: André de la Rocha <andre.rocha@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

2 files changed, 36 insertions, 19 deletions

diff --git a/src/corelib/io/qfsfileengine.cpp b/src/corelib/io/qfsfileengine.cpp
index 387990ed79..5d3bef9e70 100644
--- a/src/corelib/io/qfsfileengine.cpp
+++ b/src/corelib/io/qfsfileengine.cpp
@@ -167,19 +167,21 @@ QFSFileEngine::QFSFileEngine(QFSFileEnginePrivate &dd)
 /*!
     \internal
 */
-bool QFSFileEngine::processOpenModeFlags(QIODevice::OpenMode *mode)
+ProcessOpenModeResult processOpenModeFlags(QIODevice::OpenMode openMode)
 {
-    QIODevice::OpenMode &openMode = *mode;
+    ProcessOpenModeResult result;
+    result.ok = false;
     if ((openMode & QFile::NewOnly) && (openMode & QFile::ExistingOnly)) {
         qWarning("NewOnly and ExistingOnly are mutually exclusive");
-        setError(QFile::OpenError, QLatin1String("NewOnly and ExistingOnly are mutually exclusive"));
-        return false;
+        result.error = QLatin1String("NewOnly and ExistingOnly are mutually exclusive");
+        return result;
     }
 
     if ((openMode & QFile::ExistingOnly) && !(openMode & (QFile::ReadOnly | QFile::WriteOnly))) {
         qWarning("ExistingOnly must be specified alongside ReadOnly, WriteOnly, or ReadWrite");
-        setError(QFile::OpenError, QLatin1String("ExistingOnly must be specified alongside ReadOnly, WriteOnly, or ReadWrite"));
-        return false;
+        result.error = QLatin1String(
+                    "ExistingOnly must be specified alongside ReadOnly, WriteOnly, or ReadWrite");
+        return result;
     }
 
     // Either Append or NewOnly implies WriteOnly
@@ -190,7 +192,9 @@ bool QFSFileEngine::processOpenModeFlags(QIODevice::OpenMode *mode)
     if ((openMode & QFile::WriteOnly) && !(openMode & (QFile::ReadOnly | QFile::Append | QFile::NewOnly)))
         openMode |= QFile::Truncate;
 
-    return true;
+    result.ok = true;
+    result.openMode = openMode;
+    return result;
 }
 
 /*!
@@ -234,16 +238,19 @@ bool QFSFileEngine::open(QIODevice::OpenMode openMode)
         return false;
     }
 
-    if (!processOpenModeFlags(&openMode))
+    const ProcessOpenModeResult res = processOpenModeFlags(openMode);
+    if (!res.ok) {
+        setError(QFileDevice::OpenError, res.error);
         return false;
+    }
 
-    d->openMode = openMode;
+    d->openMode = res.openMode;
     d->lastFlushFailed = false;
     d->tried_stat = 0;
     d->fh = 0;
     d->fd = -1;
 
-    return d->nativeOpen(openMode);
+    return d->nativeOpen(d->openMode);
 }
 
 /*!
@@ -262,17 +269,20 @@ bool QFSFileEngine::open(QIODevice::OpenMode openMode, FILE *fh, QFile::FileHand
 
     Q_D(QFSFileEngine);
 
-    if (!processOpenModeFlags(&openMode))
+    const ProcessOpenModeResult res = processOpenModeFlags(openMode);
+    if (!res.ok) {
+        setError(QFileDevice::OpenError, res.error);
         return false;
+    }
 
-    d->openMode = openMode;
+    d->openMode = res.openMode;
     d->lastFlushFailed = false;
     d->closeFileHandle = (handleFlags & QFile::AutoCloseHandle);
     d->fileEntry.clear();
     d->tried_stat = 0;
     d->fd = -1;
 
-    return d->openFh(openMode, fh);
+    return d->openFh(d->openMode, fh);
 }
 
 /*!
@@ -321,10 +331,13 @@ bool QFSFileEngine::open(QIODevice::OpenMode openMode, int fd, QFile::FileHandle
 {
     Q_D(QFSFileEngine);
 
-    if (!processOpenModeFlags(&openMode))
+    const ProcessOpenModeResult res = processOpenModeFlags(openMode);
+    if (!res.ok) {
+        setError(QFileDevice::OpenError, res.error);
         return false;
+    }
 
-    d->openMode = openMode;
+    d->openMode = res.openMode;
     d->lastFlushFailed = false;
     d->closeFileHandle = (handleFlags & QFile::AutoCloseHandle);
     d->fileEntry.clear();
@@ -332,7 +345,7 @@ bool QFSFileEngine::open(QIODevice::OpenMode openMode, int fd, QFile::FileHandle
     d->fd = -1;
     d->tried_stat = 0;
 
-    return d->openFd(openMode, fd);
+    return d->openFd(d->openMode, fd);
 }
 
 
diff --git a/src/corelib/io/qfsfileengine_p.h b/src/corelib/io/qfsfileengine_p.h
index 6b091a8eef..5231b4fe6f 100644
--- a/src/corelib/io/qfsfileengine_p.h
+++ b/src/corelib/io/qfsfileengine_p.h
@@ -61,6 +61,13 @@
 
 QT_BEGIN_NAMESPACE
 
+struct ProcessOpenModeResult {
+    bool ok;
+    QIODevice::OpenMode openMode;
+    QString error;
+};
+inline Q_CORE_EXPORT ProcessOpenModeResult processOpenModeFlags(QIODevice::OpenMode mode);
+
 class QFSFileEnginePrivate;
 
 class Q_CORE_EXPORT QFSFileEngine : public QAbstractFileEngine
@@ -131,9 +138,6 @@ public:
 
 protected:
     QFSFileEngine(QFSFileEnginePrivate &dd);
-
-private:
-    inline bool processOpenModeFlags(QIODevice::OpenMode *mode);
 };
 
 class Q_AUTOTEST_EXPORT QFSFileEnginePrivate : public QAbstractFileEnginePrivate