WMF export: just write the source data as is for from-WMF graphics

This was already working on master since commit
5868745db74ae930edb0058490076d82aaeafbe9 (emfplus: make VectorFormats
Emf/Wmf/Svg work, 2017-06-12), but a matching testcase was missing.

Change-Id: I7661cd5e66d13b1750f16c0c423c4b69420577a0
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/106607
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins

2 files changed, 30 insertions, 0 deletions

diff --git a/vcl/qa/cppunit/GraphicTest.cxx b/vcl/qa/cppunit/GraphicTest.cxx
index 50ff4a133f86..df9711b54a35 100644
--- a/vcl/qa/cppunit/GraphicTest.cxx
+++ b/vcl/qa/cppunit/GraphicTest.cxx
@@ -24,6 +24,7 @@
 #include <comphelper/DirectoryHelper.hxx>
 #include <comphelper/hash.hxx>
 #include <unotools/ucbstreamhelper.hxx>
+#include <unotools/tempfile.hxx>
 
 #include <impgraph.hxx>
 
@@ -49,6 +50,7 @@ private:
     void testSwapping();
     void testSwappingVectorGraphic();
     void testSwappingPageNumber();
+    void testWMFRoundtrip();
 
     CPPUNIT_TEST_SUITE(GraphicTest);
     CPPUNIT_TEST(testUnloadedGraphic);
@@ -59,6 +61,7 @@ private:
     CPPUNIT_TEST(testSwapping);
     CPPUNIT_TEST(testSwappingVectorGraphic);
     CPPUNIT_TEST(testSwappingPageNumber);
+    CPPUNIT_TEST(testWMFRoundtrip);
     CPPUNIT_TEST_SUITE_END();
 };
 
@@ -468,6 +471,33 @@ void GraphicTest::testSwappingPageNumber()
     CPPUNIT_ASSERT_EQUAL(sal_Int32(1), aGraphic.getVectorGraphicData()->getPageIndex());
 }
 
+void GraphicTest::testWMFRoundtrip()
+{
+    // Load a WMF file.
+    test::Directories aDirectories;
+    OUString aURL = aDirectories.getURLFromSrc("vcl/qa/cppunit/data/roundtrip.wmf");
+    SvFileStream aStream(aURL, StreamMode::READ);
+    sal_uInt64 nExpectedSize = aStream.TellEnd();
+    GraphicFilter& rGraphicFilter = GraphicFilter::GetGraphicFilter();
+    Graphic aGraphic = rGraphicFilter.ImportUnloadedGraphic(aStream);
+
+    // Save as WMF.
+    utl::TempFile aTempFile;
+    aTempFile.EnableKillingFile();
+    sal_uInt16 nFormat = rGraphicFilter.GetExportFormatNumberForShortName(u"WMF");
+    SvStream& rOutStream = *aTempFile.GetStream(StreamMode::READWRITE);
+    rGraphicFilter.ExportGraphic(aGraphic, OUString(), rOutStream, nFormat);
+
+    // Check if we preserved the WMF data perfectly.
+    sal_uInt64 nActualSize = rOutStream.TellEnd();
+
+    // Without the accompanying fix in place, this test would have failed with:
+    // - Expected: 6475
+    // - Actual  : 2826
+    // i.e. we lost some of the WMF data on roundtrip.
+    CPPUNIT_ASSERT_EQUAL(nExpectedSize, nActualSize);
+}
+
 } // namespace
 
 CPPUNIT_TEST_SUITE_REGISTRATION(GraphicTest);
diff --git a/vcl/qa/cppunit/data/roundtrip.wmf b/vcl/qa/cppunit/data/roundtrip.wmf
new file mode 100644
index 000000000000..83210546c373
--- /dev/null
+++ b/vcl/qa/cppunit/data/roundtrip.wmf