UnoApiTest: check no document is open before opening a new one

Change-Id: I8abe65f88b63446dd8bfe2465c9a8d2d4aff31ea
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/199508
Reviewed-by: Xisco Fauli <xiscofauli@libreoffice.org>
Tested-by: Jenkins

test/source/unoapi_test.cxx

@@ -58,10 +58,7 @@ void UnoApiTest::tearDown()
     }
 
     if (mxComponent.is())
-    {
-        mxComponent->dispose();
-        mxComponent.clear();
-    }
+        dispose();
 
     test::BootstrapFixture::tearDown();
 }
@@ -262,11 +259,7 @@ void UnoApiTest::loadFromURL(OUString const& rURL,
     if (meImportFilterName != TestFilter::NONE)
         aMediaDescriptor[u"FilterName"_ustr] <<= TestFilterNames.at(meImportFilterName);
 
-    if (mxComponent.is())
-    {
-        mxComponent->dispose();
-        mxComponent.clear();
-    }
+    CPPUNIT_ASSERT_MESSAGE("A document is already open!", !mxComponent.is());
 
     mxComponent = loadFromDesktop(rURL, OUString(), aMediaDescriptor.getAsConstPropertyValueList());
     CPPUNIT_ASSERT(mxComponent);
@@ -359,6 +352,7 @@ void UnoApiTest::saveAndReload(TestFilter eFilter,
                                const char* pPassword)
 {
     save(eFilter, rParams, pPassword);
+    dispose();
     loadFromURL(maTempFile.GetURL(), rParams, pPassword);
 }