ODF export: sort <style:font-face> elements based on the style:name attribute

m_pFontAutoStylePool is already sorted, but sorting ignores
XMLFontAutoStylePoolEntry_Impl::sName, and changing
XMLFontAutoStylePoolEntryCmp_Impl would affect how find() works in
XMLFontAutoStylePool::Add(), so just extend
XMLFontAutoStylePool::exportXML() instead.

With this, the order of <style:font-face> elements is meant to be stable
in content.xml and styles.xml, helping use-cases where a document is
converted to ODF multiple times and an integration test wants to assert
that the output is the same.

Change-Id: If0dbfa40a1b204aebe5e141fe64f71ac2ca92405
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/112339
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins

xmloff/CppunitTest_xmloff_style.mk

@@ -13,6 +13,7 @@ $(eval $(call gb_CppunitTest_CppunitTest,xmloff_style))
 
 $(eval $(call gb_CppunitTest_use_externals,xmloff_style,\
 	boost_headers \
+	libxml2 \
 ))
 
 $(eval $(call gb_CppunitTest_add_exception_objects,xmloff_style, \
@@ -26,6 +27,7 @@ $(eval $(call gb_CppunitTest_use_libraries,xmloff_style, \
     sal \
     test \
     unotest \
+    utl \
 ))
 
 $(eval $(call gb_CppunitTest_use_sdk_api,xmloff_style))

xmloff/qa/unit/style.cxx

@@ -13,16 +13,25 @@
 
 #include <test/bootstrapfixture.hxx>
 #include <unotest/macros_test.hxx>
+#include <test/xmltesttools.hxx>
 
 #include <com/sun/star/frame/Desktop.hpp>
 #include <com/sun/star/container/XNameContainer.hpp>
+#include <com/sun/star/frame/XStorable.hpp>
+#include <com/sun/star/packages/zip/ZipFileAccess.hpp>
+
+#include <comphelper/propertysequence.hxx>
+#include <unotools/tempfile.hxx>
+#include <unotools/ucbstreamhelper.hxx>
 
 using namespace ::com::sun::star;
 
 constexpr OUStringLiteral DATA_DIRECTORY = u"/xmloff/qa/unit/data/";
 
 /// Covers xmloff/source/style/ fixes.
-class XmloffStyleTest : public test::BootstrapFixture, public unotest::MacrosTest
+class XmloffStyleTest : public test::BootstrapFixture,
+                        public unotest::MacrosTest,
+                        public XmlTestTools
 {
 private:
     uno::Reference<lang::XComponent> mxComponent;
@@ -30,6 +39,7 @@ private:
 public:
     void setUp() override;
     void tearDown() override;
+    void registerNamespaces(xmlXPathContextPtr& pXmlXpathCtx) override;
     uno::Reference<lang::XComponent>& getComponent() { return mxComponent; }
     void load(std::u16string_view rURL);
 };
@@ -49,6 +59,14 @@ void XmloffStyleTest::tearDown()
     test::BootstrapFixture::tearDown();
 }
 
+void XmloffStyleTest::registerNamespaces(xmlXPathContextPtr& pXmlXpathCtx)
+{
+    xmlXPathRegisterNs(pXmlXpathCtx, BAD_CAST("office"),
+                       BAD_CAST("urn:oasis:names:tc:opendocument:xmlns:office:1.0"));
+    xmlXPathRegisterNs(pXmlXpathCtx, BAD_CAST("style"),
+                       BAD_CAST("urn:oasis:names:tc:opendocument:xmlns:style:1.0"));
+}
+
 void XmloffStyleTest::load(std::u16string_view rFileName)
 {
     OUString aURL = m_directories.getURLFromSrc(DATA_DIRECTORY) + rFileName;
@@ -68,6 +86,55 @@ CPPUNIT_TEST_FIXTURE(XmloffStyleTest, testFillImageBase64)
     CPPUNIT_ASSERT(xBitmaps->hasByName("libreoffice_0"));
 }
 
+CPPUNIT_TEST_FIXTURE(XmloffStyleTest, testFontSorting)
+{
+    // Given an empty document with default fonts (Liberation Sans, Lucida Sans, etc):
+    getComponent() = loadFromDesktop("private:factory/swriter");
+
+    // When saving that document to ODT:
+    uno::Reference<frame::XStorable> xStorable(getComponent(), uno::UNO_QUERY);
+    utl::TempFile aTempFile;
+    aTempFile.EnableKillingFile();
+    uno::Sequence<beans::PropertyValue> aStoreProps = comphelper::InitPropertySequence({
+        { "FilterName", uno::makeAny(OUString("writer8")) },
+    });
+    xStorable->storeToURL(aTempFile.GetURL(), aStoreProps);
+
+    // Then make sure <style:font-face> elements are sorted (by style:name="..."):
+    uno::Reference<packages::zip::XZipFileAccess2> xNameAccess
+        = packages::zip::ZipFileAccess::createWithURL(mxComponentContext, aTempFile.GetURL());
+    uno::Reference<io::XInputStream> xInputStream(xNameAccess->getByName("content.xml"),
+                                                  uno::UNO_QUERY);
+    std::unique_ptr<SvStream> pStream(utl::UcbStreamHelper::CreateStream(xInputStream, true));
+    xmlDocUniquePtr pXmlDoc = parseXmlStream(pStream.get());
+    xmlXPathObjectPtr pXPath
+        = getXPathNode(pXmlDoc, "/office:document-content/office:font-face-decls/style:font-face");
+    xmlNodeSetPtr pXmlNodes = pXPath->nodesetval;
+    int nNodeCount = xmlXPathNodeSetGetLength(pXmlNodes);
+    std::vector<OString> aXMLNames;
+    std::set<OString> aSortedNames;
+    for (int i = 0; i < nNodeCount; ++i)
+    {
+        xmlNodePtr pXmlNode = pXmlNodes->nodeTab[i];
+        xmlChar* pName = xmlGetProp(pXmlNode, BAD_CAST("name"));
+        OString aName(reinterpret_cast<char const*>(pName));
+        aXMLNames.push_back(aName);
+        aSortedNames.insert(aName);
+        xmlFree(pName);
+    }
+    size_t nIndex = 0;
+    for (const auto& rName : aSortedNames)
+    {
+        // Without the accompanying fix in place, this test would have failed with:
+        // - Expected: Liberation Sans
+        // - Actual  : Lucida Sans1
+        // i.e. the output was not lexicographically sorted, "u" was before "i".
+        CPPUNIT_ASSERT_EQUAL(rName, aXMLNames[nIndex]);
+        ++nIndex;
+    }
+    xmlXPathFreeObject(pXPath);
+}
+
 CPPUNIT_PLUGIN_IMPLEMENT();
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

xmloff/source/style/XMLFontAutoStylePool.cxx

@@ -406,7 +406,19 @@ void XMLFontAutoStylePool::exportXML()
     if (m_bEmbedUsedOnly)
         aUsedFontNames = getUsedFontList();
 
+    // Sort <style:font-face> elements based on their style:name attribute.
+    std::vector<XMLFontAutoStylePoolEntry_Impl*> aFontAutoStyles;
     for (const auto& pEntry : *m_pFontAutoStylePool)
+    {
+        aFontAutoStyles.push_back(pEntry.get());
+    }
+    std::sort(
+        aFontAutoStyles.begin(), aFontAutoStyles.end(),
+        [](const XMLFontAutoStylePoolEntry_Impl* pA, XMLFontAutoStylePoolEntry_Impl* pB) -> bool {
+            return pA->GetName() < pB->GetName();
+        });
+
+    for (const auto& pEntry : aFontAutoStyles)
     {
         GetExport().AddAttribute(XML_NAMESPACE_STYLE, XML_NAME, pEntry->GetName());