Fix CreateFileMapping() error handling

CreateFileMapping() returns NULL in case of an error.
The patch corrects the wrong testing on INVALID_HANDLE_VALUE, and sets
NULL for invalid handles.

Change-Id: Iaab4945ed88ee92bbf9a0871e95a5820dd1a56ed
(cherry-picked from qtbase/1a8f67938c4146614fec3788c7868dc1a314cc84)
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>

2 files changed, 5 insertions, 4 deletions

diff --git a/src/corelib/io/qfsfileengine.cpp b/src/corelib/io/qfsfileengine.cpp
index c2d70b6..929a369 100644
--- a/src/corelib/io/qfsfileengine.cpp
+++ b/src/corelib/io/qfsfileengine.cpp
@@ -132,7 +132,7 @@ void QFSFileEnginePrivate::init()
 #ifdef Q_OS_WIN
     fileAttrib = INVALID_FILE_ATTRIBUTES;
     fileHandle = INVALID_HANDLE_VALUE;
-    mapHandle = INVALID_HANDLE_VALUE;
+    mapHandle = NULL;
 #ifndef Q_OS_WINCE
     cachedFd = -1;
 #endif
diff --git a/src/corelib/io/qfsfileengine_win.cpp b/src/corelib/io/qfsfileengine_win.cpp
index 8ee18e9..7a80b9a 100644
--- a/src/corelib/io/qfsfileengine_win.cpp
+++ b/src/corelib/io/qfsfileengine_win.cpp
@@ -910,7 +910,7 @@ uchar *QFSFileEnginePrivate::map(qint64 offset, qint64 size,
         return 0;
     }
 
-    if (mapHandle == INVALID_HANDLE_VALUE) {
+    if (mapHandle == NULL) {
         // get handle to the file
         HANDLE handle = fileHandle;
 
@@ -943,7 +943,7 @@ uchar *QFSFileEnginePrivate::map(qint64 offset, qint64 size,
         // first create the file mapping handle
         DWORD protection = (openMode & QIODevice::WriteOnly) ? PAGE_READWRITE : PAGE_READONLY;
         mapHandle = ::CreateFileMapping(handle, 0, protection, 0, 0, 0);
-        if (mapHandle == INVALID_HANDLE_VALUE) {
+        if (mapHandle == NULL) {
             q->setError(QFile::PermissionsError, qt_error_string());
 #ifdef Q_USE_DEPRECATED_MAP_API
             ::CloseHandle(handle);
@@ -986,6 +986,7 @@ uchar *QFSFileEnginePrivate::map(qint64 offset, qint64 size,
     }
 
     ::CloseHandle(mapHandle);
+    mapHandle = NULL;
     return 0;
 }
 
@@ -1005,7 +1006,7 @@ bool QFSFileEnginePrivate::unmap(uchar *ptr)
     maps.remove(ptr);
     if (maps.isEmpty()) {
         ::CloseHandle(mapHandle);
-        mapHandle = INVALID_HANDLE_VALUE;
+        mapHandle = NULL;
     }
 
     return true;