sfx2: allow storeToURL() on the main thread

This is similar to commit f1e77547
(framework: allow storeSelf() on the main thread, 2019-01-30), just this
handles "save as" instead of "save".

The result is that combining this commit with the previous OnMainThread
ones allows all of document load/save/save-as/command-dispatch on the
main thread even when the action is invoked via remote UNO, which would
run on a non-main thread by default.

Change-Id: I7d50cceb66ecc6619fe25734107a2524ca872c2a
Reviewed-on: https://gerrit.libreoffice.org/67412Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins

include/sfx2/sfxbasemodel.hxx

@@ -407,6 +407,9 @@ public:
     virtual void SAL_CALL storeToURL(   const   OUString& sURL,
                                         const   css::uno::Sequence< css::beans::PropertyValue >&   seqArguments    ) override;
 
+    SAL_DLLPRIVATE void
+    impl_store(const OUString& sURL,
+               const css::uno::Sequence<css::beans::PropertyValue>& seqArguments, bool bSaveTo);
 
     //  XLoadable
 
@@ -715,10 +718,6 @@ private:
     SAL_DLLPRIVATE void ListenForStorage_Impl( const css::uno::Reference< css::embed::XStorage >& xStorage );
     SAL_DLLPRIVATE OUString GetMediumFilterName_Impl();
 
-    SAL_DLLPRIVATE void impl_store( const OUString& sURL,
-                        const   css::uno::Sequence< css::beans::PropertyValue >&   seqArguments    ,
-                                bool                    bSaveTo         ) ;
-
     SAL_DLLPRIVATE void postEvent_Impl( const OUString& aName, const css::uno::Reference< css::frame::XController2 >& xController = css::uno::Reference< css::frame::XController2 >() );
 
     SAL_DLLPRIVATE css::uno::Reference< css::frame::XTitle > impl_getTitleHelper ();

sfx2/source/doc/sfxbasemodel.cxx

@@ -126,7 +126,7 @@
 #include <sfx2/sfxresid.hxx>
 #include <comphelper/profilezone.hxx>
 #include <vcl/threadex.hxx>
-
+#include <unotools/mediadescriptor.hxx>
 
 //  namespaces
 
@@ -1504,6 +1504,17 @@ static bool SaveImplStatic(SfxObjectShell* pThis, const SfxItemSet* pParams)
     return pThis->Save_Impl(pParams);
 }
 
+/**
+ * Proxy around SfxBaseModel::impl_store(), as vcl::solarthread::syncExecute()
+ * does not seem to accept lambdas or void functions.
+ */
+static bool ImplStoreStatic(SfxBaseModel* pThis, const OUString& rURL,
+                            const uno::Sequence<beans::PropertyValue>& rArgs, bool bSaveTo)
+{
+    pThis->impl_store(rURL, rArgs, bSaveTo);
+    return true;
+}
+
 //  XStorable2
 
 
@@ -1688,7 +1699,12 @@ void SAL_CALL SfxBaseModel::storeToURL( const   OUString&                   rURL
     {
         SfxSaveGuard aSaveGuard(this, m_pData.get());
         try {
-            impl_store(rURL, rArgs, true);
+            utl::MediaDescriptor aDescriptor(rArgs);
+            bool bOnMainThread = aDescriptor.getUnpackedValueOrDefault("OnMainThread", false);
+            if (bOnMainThread)
+                vcl::solarthread::syncExecute(std::bind(&ImplStoreStatic, this, rURL, rArgs, true));
+            else
+                impl_store(rURL, rArgs, true);
         }
         catch (const uno::Exception &e)
         {