whytofly
/
qt6-bb10
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Improved Windows printer support and fixed crashes due to NULL devMode 

With certain printer drivers, the PRINTER_INFO_2 can return NULL for
the pDevMode member in the call to GetPrinter() as mentioned on MSDN:
https://msdn.microsoft.com/en-us/library/windows/desktop/dd144911
In many places, Qt first checks that devMode isn't NULL before
dereferencing it.  In other places it does not (such as when it
actually attempts to print in QWin32PrintEngine::begin()).  Checking
every dereference aside, most printer functionality is removed without
access to the DEVMODE structure.  This fix uses DocumentProperties()
to get the DEVMODE information when the first method fails.

[ChangeLog][QtPrintSupport][QPrinter][Windows] Improved Windows printer
support and fixed crashes due to NULL devMode

Task-number: QTBUG-44349
Task-number: QTBUG-43877
Task-number: QTBUG-2251
Change-Id: Iafa337055d967c70f2096dcde4cc9c8ca8a0d252
Reviewed-by: Andy Shaw <andy.shaw@digia.com>
bb10
Mike Kuta 2015-02-06 11:34:28 -05:00 committed by Andy Shaw
parent 208cd9ebf1
commit 4ca43c71eb
4 changed files with 75 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
src/plugins/printsupport/windows/qwindowsprintdevice.cpp
View File

@ -248,8 +248,20 @@ QMarginsF QWindowsPrintDevice::printableMargins(const QPageSize &pageSize,
if (GetPrinter(m_hPrinter, 2, buffer.data(), needed, &needed)) {
PPRINTER_INFO_2 info = reinterpret_cast<PPRINTER_INFO_2>(buffer.data());
DEVMODE *devMode = info->pDevMode;
if (!devMode)
return margins;
bool separateDevMode = false;
if (!devMode) {
// GetPrinter() didn't include the DEVMODE. Get it a different way.
LONG result = DocumentProperties(NULL, m_hPrinter, (LPWSTR)m_id.utf16(),
NULL, NULL, 0);
devMode = (DEVMODE *)malloc(result);
separateDevMode = true;
result = DocumentProperties(NULL, m_hPrinter, (LPWSTR)m_id.utf16(),
devMode, NULL, DM_OUT_BUFFER);
if (result != IDOK) {
free(devMode);
return margins;
}
}
HDC pDC = CreateDC(NULL, (LPWSTR)m_id.utf16(), NULL, devMode);
if (pageSize.id() == QPageSize::Custom || pageSize.windowsId() <= 0 || pageSize.windowsId() > DMPAPER_LAST) {
@ -275,6 +287,8 @@ QMarginsF QWindowsPrintDevice::printableMargins(const QPageSize &pageSize,
const qreal rightMargin = physicalWidth - leftMargin - printableWidth;
const qreal bottomMargin = physicalHeight - topMargin - printableHeight;
margins = QMarginsF(leftMargin, topMargin, rightMargin, bottomMargin);
if (separateDevMode)
free(devMode);
DeleteDC(pDC);
}
return margins;

7
src/printsupport/dialogs/qpagesetupdialog_win.cpp
View File

@ -134,6 +134,13 @@ int QPageSetupDialog::exec()
// copy from our temp DEVMODE struct
if (!engine->globalDevMode() && hDevMode) {
// Make sure memory is allocated
if (ep->ownsDevMode && ep->devMode)
free(ep->devMode);
ep->devMode = (DEVMODE *) malloc(devModeSize);
ep->ownsDevMode = true;
// Copy
void *src = GlobalLock(hDevMode);
memcpy(ep->devMode, src, devModeSize);
GlobalUnlock(hDevMode);

53
src/printsupport/kernel/qprintengine_win.cpp
View File

@ -855,7 +855,8 @@ void QWin32PrintEnginePrivate::initialize()
txop = QTransform::TxNone;
bool ok = OpenPrinter((LPWSTR)m_printDevice.id().utf16(), (LPHANDLE)&hPrinter, 0);
QString printerName = m_printDevice.id();
bool ok = OpenPrinter((LPWSTR)printerName.utf16(), (LPHANDLE)&hPrinter, 0);
if (!ok) {
qErrnoWarning("QWin32PrintEngine::initialize: OpenPrinter failed");
return;
@ -876,7 +877,32 @@ void QWin32PrintEnginePrivate::initialize()
}
devMode = pInfo->pDevMode;
hdc = CreateDC(NULL, reinterpret_cast<const wchar_t *>(m_printDevice.id().utf16()), 0, devMode);
if (!devMode) {
// pInfo->pDevMode == NULL for some printers and passing NULL
// into CreateDC leads to the printer doing nothing. In addition,
// the framework assumes that devMode isn't NULL, such as in
// QWin32PrintEngine::begin() and QPageSetupDialog::exec()
// Attempt to get the DEVMODE a different way.
// Allocate the required buffer
LONG result = DocumentProperties(NULL, hPrinter, (LPWSTR)printerName.utf16(),
NULL, NULL, 0);
devMode = (DEVMODE *) malloc(result);
ownsDevMode = true;
// Get the default DevMode
result = DocumentProperties(NULL, hPrinter, (LPWSTR)printerName.utf16(),
devMode, NULL, DM_OUT_BUFFER);
if (result != IDOK) {
qErrnoWarning("QWin32PrintEngine::initialize: Failed to obtain devMode");
free(devMode);
devMode = NULL;
ownsDevMode = false;
}
}
hdc = CreateDC(NULL, (LPCWSTR)printerName.utf16(), 0, devMode);
if (!hdc) {
qErrnoWarning("QWin32PrintEngine::initialize: CreateDC failed");
@ -939,8 +965,7 @@ void QWin32PrintEnginePrivate::release()
{
if (globalDevMode) { // Devmode comes from print dialog
GlobalUnlock(globalDevMode);
} else if (hMem) { // Devmode comes from initialize...
// devMode is a part of the same memory block as pInfo so one free is enough...
} else if (hMem) {
GlobalUnlock(hMem);
GlobalFree(hMem);
}
@ -949,11 +974,16 @@ void QWin32PrintEnginePrivate::release()
if (hdc)
DeleteDC(hdc);
// Check if devMode was allocated separately from pInfo / hMem.
if (ownsDevMode)
free(devMode);
hdc = 0;
hPrinter = 0;
pInfo = 0;
hMem = 0;
devMode = 0;
ownsDevMode = false;
}
void QWin32PrintEnginePrivate::doReinit()
@ -1233,6 +1263,8 @@ void QWin32PrintEngine::setProperty(PrintEnginePropertyKey key, const QVariant &
}
case PPK_QPageSize: {
if (!d->devMode)
break;
// Get the page size from the printer if supported
const QPageSize pageSize = value.value<QPageSize>();
if (pageSize.isValid()) {
@ -1303,7 +1335,10 @@ QVariant QWin32PrintEngine::property(PrintEnginePropertyKey key) const
break;
case PPK_CollateCopies:
value = d->devMode->dmCollate == DMCOLLATE_TRUE;
if (!d->devMode)
value = false;
else
value = d->devMode->dmCollate == DMCOLLATE_TRUE;
break;
case PPK_ColorMode:
@ -1513,6 +1548,10 @@ void QWin32PrintEngine::setGlobalDevMode(HGLOBAL globalDevNames, HGLOBAL globalD
DEVMODE *dm = (DEVMODE*) GlobalLock(globalDevMode);
d->release();
d->globalDevMode = globalDevMode;
if (d->ownsDevMode) {
free(d->devMode);
d->ownsDevMode = false;
}
d->devMode = dm;
d->hdc = CreateDC(NULL, reinterpret_cast<const wchar_t *>(d->m_printDevice.id().utf16()), 0, dm);
@ -1543,6 +1582,8 @@ void QWin32PrintEnginePrivate::setPageSize(const QPageSize &pageSize)
if (!pageSize.isValid())
return;
Q_ASSERT(devMode);
// Use the printer page size if supported
const QPageSize printerPageSize = m_printDevice.supportedPageSize(pageSize);
const QPageSize usePageSize = printerPageSize.isValid() ? printerPageSize : pageSize;
@ -1571,6 +1612,8 @@ void QWin32PrintEnginePrivate::setPageSize(const QPageSize &pageSize)
// Update the page layout after any changes made to devMode
void QWin32PrintEnginePrivate::updatePageLayout()
{
Q_ASSERT(devMode);
// Update orientation first as is needed to obtain printable margins when changing page size
m_pageLayout.setOrientation(devMode->dmOrientation == DMORIENT_LANDSCAPE ? QPageLayout::Landscape : QPageLayout::Portrait);
if (devMode->dmPaperSize >= DMPAPER_USER) {

4
src/printsupport/kernel/qprintengine_win_p.h
View File

@ -119,6 +119,7 @@ public:
pInfo(0),
hMem(0),
hdc(0),
ownsDevMode(false),
mode(QPrinter::ScreenResolution),
state(QPrinter::Idle),
resolution(0),
@ -179,6 +180,9 @@ public:
HDC hdc;
// True if devMode was allocated separately from pInfo.
bool ownsDevMode;
QPrinter::PrinterMode mode;
// Print Device