sfx2: fix locking after signing OOXML documents

File -> digital signatures looks like a way to view and modify digital
signatures, internally it's a sign action, that at the end may not modify
signatures after all. For this to work, SfxObjectShell::ImplSign() calls
GetMedium()->CloseAndRelease() to release the document's lock file, invokes the
signing dialog, then DoSaveCompleted() creates the lockfile again.

When signing OOXML documents, the lock file is not re-created, as
DoSaveCompleted() only creates the lockfile in case
IsPackageStorageFormat_Impl() (== own format) is true. Fix this by adding a
mode that creates the lock file, even in case of a foreign format.

With this, closing the digital signatures dialog for OOXML documents no longer
results in a confusing "Document in Use" dialog after closing the signatures
dialog.

Change-Id: Ie9e56b88768825e61765669b27a89082cdc1981f

sfx2/source/doc/objserv.cxx

@@ -1486,7 +1486,9 @@ void SfxObjectShell::ImplSign( bool bScriptingContent )
             || pImp->nDocumentSignatureState == SignatureState::NOTVALIDATED
             || pImp->nDocumentSignatureState == SignatureState::PARTIAL_OK);
 
+        pImp->m_bSavingForSigning = true;
         DoSaveCompleted( GetMedium() );
+        pImp->m_bSavingForSigning = false;
 
         if ( bSigned )
         {

sfx2/source/doc/objstor.cxx

@@ -2009,6 +2009,12 @@ bool SfxObjectShell::DoSaveCompleted( SfxMedium* pNewMed )
         }
         else
         {
+            if (pImp->m_bSavingForSigning && pFilter && pFilter->GetSupportsSigning())
+                // So that pMedium->pImp->xStream becomes a non-empty
+                // reference, and at the end we attempt locking again in
+                // SfxMedium::LockOrigFileOnDemand().
+                pMedium->GetMedium_Impl();
+
             if( pMedium->GetOpenMode() & StreamMode::WRITE )
                 pMedium->GetInStream();
             xStorage = GetStorage();

sfx2/source/doc/objxtor.cxx

@@ -264,6 +264,7 @@ SfxObjectShell_Impl::SfxObjectShell_Impl( SfxObjectShell& _rDocShell )
     ,m_bIncomplEncrWarnShown( false )
     ,m_nModifyPasswordHash( 0 )
     ,m_bModifyPasswordEntered( false )
+    ,m_bSavingForSigning( false )
 {
     SfxObjectShell* pDoc = &_rDocShell;
     SfxObjectShellArr_Impl &rArr = SfxGetpApp()->GetObjectShells_Impl();

sfx2/source/inc/objshimp.hxx

@@ -146,6 +146,8 @@ struct SfxObjectShell_Impl : public ::sfx2::IMacroDocumentAccess
     sal_uInt32          m_nModifyPasswordHash;
     css::uno::Sequence< css::beans::PropertyValue > m_aModifyPasswordInfo;
     bool                m_bModifyPasswordEntered;
+    /// If true, then this is not a real save, just the signatures change.
+    bool m_bSavingForSigning;
 
     SfxObjectShell_Impl( SfxObjectShell& _rDocShell );
     virtual ~SfxObjectShell_Impl();