simplify some OUString::concat usage

Change-Id: Ifa150dc9d694981ffe03c254ea8c3fd820c99795
Reviewed-on: https://gerrit.libreoffice.org/39812Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

dbaccess/source/core/dataaccess/databasedocument.cxx

@@ -372,8 +372,8 @@ void lcl_uglyHackToStoreDialogeEmbedImages( const Reference< XStorageBasedLibrar
             for ( sal_Int32 j=0; j < nDialogs; ++j )
             {
                 Reference < awt::XDialogProvider > xDlgPrv = awt::DialogProvider::createWithModel(rxContext, rxModel);
-                OUString sDialogUrl = "vnd.sun.star.script:";
-                sDialogUrl = sDialogUrl.concat( sLibraries[ i ] ).concat( "." ).concat (  sDialogs[ j ]  ).concat( "?location=document" );
+                OUString sDialogUrl =
+                    "vnd.sun.star.script:" + sLibraries[i] + "." + sDialogs[j] + "?location=document";
 
                 Reference< css::awt::XControl > xDialog( xDlgPrv->createDialog( sDialogUrl ), UNO_QUERY );
                 Reference< XInterface > xModel( xDialog->getModel() );

filter/source/xmlfilteradaptor/XmlFilterAdaptor.cxx

@@ -134,9 +134,7 @@ bool SAL_CALL XmlFilterAdaptor::importImpl( const Sequence< css::beans::Property
             if(!comphelper::isFileUrl(msTemplateName))
             {
                 SvtPathOptions aOptions;
-                OUString PathString = aOptions.SubstituteVariable("$(progurl)");
-                PathString = PathString.concat("/");
-                msTemplateName=PathString.concat(msTemplateName);
+                msTemplateName = aOptions.SubstituteVariable("$(progurl)") + "/" + msTemplateName;
             }
 
             xstyleLoader->loadStylesFromURL(msTemplateName,aValue);

framework/source/fwe/xml/menudocumenthandler.cxx

@@ -872,7 +872,7 @@ void OWriteMenuDocumentHandler::WriteMenuItem( const OUString& aCommandURL, cons
             if ( nStyle & pStyle->nBit )
             {
                 if ( !aValue.isEmpty() )
-                    aValue = aValue.concat( "+" );
+                    aValue += "+";
                 aValue += OUString::createFromAscii( pStyle->attrName );
             }
         }

framework/source/fwe/xml/toolboxdocumenthandler.cxx

@@ -719,7 +719,7 @@ void OWriteToolBoxDocumentHandler::WriteToolBoxItem(
             if ( nStyle & pStyle->nBit )
             {
                 if ( !aValue.isEmpty() )
-                    aValue = aValue.concat( " " );
+                    aValue += " ";
                 aValue += OUString::createFromAscii( pStyle->attrName );
             }
         }

oox/source/drawingml/hyperlinkcontext.cxx

@@ -94,8 +94,7 @@ HyperLinkContext::HyperLinkContext( ContextHandler2Helper& rParent,
                 if ( aPPAct.match( sJump, nIndex + 1 ) )
                 {
                     OUString aDestination( aPPAct.copy( nIndex + 1 + sJump.getLength() ) );
-                    sURL = sURL.concat( "#action?jump=" );
-                    sURL = sURL.concat( aDestination );
+                    sURL += "#action?jump=" + aDestination;
                 }
             }
             else if ( aPPAction.match( sHlinksldjump ) )

scripting/source/basprov/basprov.cxx

@@ -293,10 +293,9 @@ namespace basprov
 
         if ( !uriRef.is() || !sfUri.is() )
         {
-            OUString errorMsg("BasicProviderImpl::getScript: failed to parse URI: ");
-            errorMsg = errorMsg.concat( scriptURI );
             throw provider::ScriptFrameworkErrorException(
-                errorMsg, Reference< XInterface >(),
+                "BasicProviderImpl::getScript: failed to parse URI: " + scriptURI,
+                Reference< XInterface >(),
                 scriptURI, "Basic",
                 provider::ScriptFrameworkErrorType::MALFORMED_URL );
         }

scripting/source/provider/MasterScriptProvider.cxx

@@ -197,8 +197,7 @@ void MasterScriptProvider::createPkgProvider()
     try