fix grayscale jpeg writing in pdfexport (tdf#121615)

If the bitmap to be written is non-8bit, e.g. in case of using OpenGL
(on Linux the test requires "SAL_FORCEGL=1 SAL_USE_VCLPLUGIN=gen",
on Windows it's probably the default case), then the bitmap is not
in native format for 8bit. This was done correctly by 45e8e0fb
that introduced it but somehow it got lost later (I can't even find
where).

Change-Id: Ib1810cb9cf12e373c1cb41da40fa28e96ad7db28
Reviewed-on: https://gerrit.libreoffice.org/69213
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

vcl/qa/cppunit/pdfexport/pdfexport.cxx

@@ -30,9 +30,19 @@
 #include <fpdf_edit.h>
 #include <fpdf_text.h>
 #include <fpdfview.h>
+#include <vcl/graphicfilter.hxx>
 
 using namespace ::com::sun::star;
 
+static std::ostream& operator<<(std::ostream& rStrm, const Color& rColor)
+{
+    rStrm << "Color: R:" << static_cast<int>(rColor.GetRed())
+          << " G:" << static_cast<int>(rColor.GetGreen())
+          << " B:" << static_cast<int>(rColor.GetBlue())
+          << " A:" << static_cast<int>(rColor.GetTransparency());
+    return rStrm;
+}
+
 namespace
 {
 
@@ -118,6 +128,7 @@ public:
     void testTdf113143();
     void testTdf115262();
     void testTdf121962();
+    void testTdf121615();
 
     CPPUNIT_TEST_SUITE(PdfExportTest);
     CPPUNIT_TEST(testTdf106059);
@@ -152,6 +163,7 @@ public:
     CPPUNIT_TEST(testTdf113143);
     CPPUNIT_TEST(testTdf115262);
     CPPUNIT_TEST(testTdf121962);
+    CPPUNIT_TEST(testTdf121615);
     CPPUNIT_TEST_SUITE_END();
 };
 
@@ -1672,6 +1684,52 @@ void PdfExportTest::testTdf121962()
     }
 }
 
+void PdfExportTest::testTdf121615()
+{
+    vcl::filter::PDFDocument aDocument;
+    load("tdf121615.odt", aDocument);
+
+    // The document has one page.
+    std::vector<vcl::filter::PDFObjectElement*> aPages = aDocument.GetPages();
+    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(1), aPages.size());
+
+    // Get access to the only image on the only page.
+    vcl::filter::PDFObjectElement* pResources = aPages[0]->LookupObject("Resources");
+    CPPUNIT_ASSERT(pResources);
+    auto pXObjects = dynamic_cast<vcl::filter::PDFDictionaryElement*>(pResources->Lookup("XObject"));
+    CPPUNIT_ASSERT(pXObjects);
+    CPPUNIT_ASSERT_EQUAL(static_cast<size_t>(1), pXObjects->GetItems().size());
+    vcl::filter::PDFObjectElement* pXObject = pXObjects->LookupObject(pXObjects->GetItems().begin()->first);
+    CPPUNIT_ASSERT(pXObject);
+    vcl::filter::PDFStreamElement* pStream = pXObject->GetStream();
+    CPPUNIT_ASSERT(pStream);
+    SvMemoryStream& rObjectStream = pStream->GetMemory();
+
+    // Load the embedded image.
+    rObjectStream.Seek( 0 );
+    GraphicFilter& rFilter = GraphicFilter::GetGraphicFilter();
+    Graphic aGraphic;
+    sal_uInt16 format;
+    ErrCode bResult = rFilter.ImportGraphic(aGraphic, OUString( "import" ), rObjectStream,
+        GRFILTER_FORMAT_DONTKNOW, &format);
+    CPPUNIT_ASSERT_EQUAL(ERRCODE_NONE, bResult);
+
+    // The image should be grayscale 8bit JPEG.
+    sal_uInt16 jpegFormat = rFilter.GetImportFormatNumberForShortName( JPG_SHORTNAME );
+    CPPUNIT_ASSERT( jpegFormat != GRFILTER_FORMAT_NOTFOUND );
+    CPPUNIT_ASSERT_EQUAL( jpegFormat, format );
+    BitmapEx aBitmap = aGraphic.GetBitmapEx();
+    CPPUNIT_ASSERT_EQUAL( 200L, aBitmap.GetSizePixel().Width());
+    CPPUNIT_ASSERT_EQUAL( 300L, aBitmap.GetSizePixel().Height());
+    CPPUNIT_ASSERT_EQUAL( 8, int(aBitmap.GetBitCount()));
+    // tdf#121615 was caused by broken handling of data width with 8bit color,
+    // so the test image has some black in the bottomright corner, check it's there
+    CPPUNIT_ASSERT_EQUAL( COL_WHITE, aBitmap.GetPixelColor( 0, 0 ));
+    CPPUNIT_ASSERT_EQUAL( COL_WHITE, aBitmap.GetPixelColor( 0, 299 ));
+    CPPUNIT_ASSERT_EQUAL( COL_WHITE, aBitmap.GetPixelColor( 199, 0 ));
+    CPPUNIT_ASSERT_EQUAL( COL_BLACK, aBitmap.GetPixelColor( 199, 299 ));
+}
+
 CPPUNIT_TEST_SUITE_REGISTRATION(PdfExportTest);
 
 }

vcl/source/filter/jpeg/JpegWriter.cxx

@@ -230,7 +230,10 @@ bool JPEGWriter::Write( const Graphic& rGraphic )
         if( mpExpWasGrey )
             *mpExpWasGrey = mbGreys;
 
-        mbNative = ( mpReadAccess->GetScanlineFormat() == ScanlineFormat::N24BitTcRgb );
+        if ( mbGreys )
+            mbNative = ( mpReadAccess->GetScanlineFormat() == ScanlineFormat::N8BitPal );
+        else
+            mbNative = ( mpReadAccess->GetScanlineFormat() == ScanlineFormat::N24BitTcRgb );
 
         if( !mbNative )
             mpBuffer = new sal_uInt8[ AlignedWidth4Bytes( mbGreys ? mpReadAccess->Width() * 8L : mpReadAccess->Width() * 24L ) ];