tdf#92524 ooxmlexport: recognize COL_AUTO for RES_BACKGROUND

FormatBackground was always returning the actual color
instead of AUTO when the color was COL_AUTO because ConvertColor
is being passed Color.GetRGBColor() instead of just Color.

There are three sections here:
-XML_fillcolor: looks like it accepts values like "green" and
"teal". Unclear from documenation whether auto is allowed.
-XML_srgbClr: only accepts rgb number, not auto
-XML_fill: needs this fix - test document available.

Since the section can't globally handle "auto", I left XML_fillcolor
alone, waiting for a proof bug report.

Change-Id: Idecb6a32fba814a6fb3aeb6cc015d793ba6f8cf9
Reviewed-on: https://gerrit.libreoffice.org/43975
Reviewed-by: Justin Luth <justin_luth@sil.org>
Tested-by: Justin Luth <justin_luth@sil.org>

sw/CppunitTest_sw_ooxmlexport11.mk

@@ -0,0 +1,14 @@
+# -*- Mode: makefile-gmake; tab-width: 4; indent-tabs-mode: t -*-
+#*************************************************************************
+#
+# This file is part of the LibreOffice project.
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+#*************************************************************************
+
+$(eval $(call sw_ooxmlexport_test,11))
+
+# vim: set noet sw=4 ts=4:

sw/Module_sw.mk

@@ -65,6 +65,7 @@ $(eval $(call gb_Module_add_slowcheck_targets,sw,\
     CppunitTest_sw_ooxmlexport8 \
     CppunitTest_sw_ooxmlexport9 \
     CppunitTest_sw_ooxmlexport10 \
+    CppunitTest_sw_ooxmlexport11 \
     CppunitTest_sw_ooxmlfieldexport \
     CppunitTest_sw_ooxmlw14export \
     CppunitTest_sw_ooxmlencryption \

sw/qa/extras/ooxmlexport/ooxmlexport11.cxx

@@ -0,0 +1,51 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <swmodeltestbase.hxx>
+
+#include <com/sun/star/awt/Size.hpp>
+#include <com/sun/star/beans/XPropertySet.hpp>
+#include <com/sun/star/text/XFootnote.hpp>
+#include <com/sun/star/text/XPageCursor.hpp>
+#include <com/sun/star/text/XTextColumns.hpp>
+#include <com/sun/star/text/XTextFrame.hpp>
+#include <com/sun/star/text/XTextFramesSupplier.hpp>
+#include <com/sun/star/text/XTextEmbeddedObjectsSupplier.hpp>
+#include <com/sun/star/text/XTextViewCursorSupplier.hpp>
+#include <com/sun/star/graphic/XGraphic.hpp>
+
+
+#include <sfx2/docfile.hxx>
+#include <sfx2/docfilt.hxx>
+#include <svx/xfillit0.hxx>
+
+class Test : public SwModelTestBase
+{
+public:
+    Test() : SwModelTestBase("/sw/qa/extras/ooxmlexport/data/", "Office Open XML Text") {}
+
+protected:
+    /**
+     * Blacklist handling
+     */
+    bool mustTestImportOf(const char* filename) const override {
+        // If the testcase is stored in some other format, it's pointless to test.
+        return OString(filename).endsWith(".docx");
+    }
+};
+
+DECLARE_OOXMLEXPORT_TEST(testTdf92524_autoColor, "tdf92524_autoColor.doc")
+{
+    CPPUNIT_ASSERT_EQUAL(drawing::FillStyle_NONE, getProperty<drawing::FillStyle>(getParagraph(1), "FillStyle"));
+    CPPUNIT_ASSERT_EQUAL(COL_AUTO, getProperty<sal_uInt32>(getParagraph(1), "ParaBackColor"));
+}
+
+CPPUNIT_PLUGIN_IMPLEMENT();
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

sw/source/filter/ww8/docxattributeoutput.cxx

@@ -8109,7 +8109,8 @@ boost::optional<sal_Int32> lcl_getDmlAlpha(const SvxBrushItem& rBrush)
 
 void DocxAttributeOutput::FormatBackground( const SvxBrushItem& rBrush )
 {
-    OString sColor = msfilter::util::ConvertColor( rBrush.GetColor().GetRGBColor() );
+    const Color aColor = rBrush.GetColor();
+    OString sColor = msfilter::util::ConvertColor( aColor.GetRGBColor() );
     boost::optional<sal_Int32> oAlpha = lcl_getDmlAlpha(rBrush);
     if (m_rExport.SdrExporter().getTextFrameSyntax())
     {
@@ -8159,6 +8160,9 @@ void DocxAttributeOutput::FormatBackground( const SvxBrushItem& rBrush )
         OString sOriginalFill = OUStringToOString(
                 m_sOriginalBackgroundColor, RTL_TEXTENCODING_UTF8 );
 
+        if ( aColor == COL_AUTO )
+            sColor = "auto";
+
         if( !m_pBackgroundAttrList.is() )
         {
             m_pBackgroundAttrList = FastSerializerHelper::createAttrList();