Created attachment 120835 [details]
Test file

Overview:
After save a copy or an autosave, when you try to save, this error occurs "The File could not be written".

Steps to Reproduce:
The document only contains an empty macro which is signed.
1) Open the document
2) Enable or disable macro (not important)
3) Save a copy or edit and wait for autosave
4) Save


Actual Results:
Impossible to save after an autosave or a save a copy

Build Date & Hardware:
Linux (4.2.0-18-generic #22-Ubuntu SMP) - 5.1 (master)
Linux (4.2.0-18-generic #22-Ubuntu SMP) - 5.0 RC
Linux (4.2.0-18-generic #22-Ubuntu SMP) - 4.4.7
Linux (4.2.0-18-generic #22-Ubuntu SMP) - 4.3.7
Windows - 4.3.7
Windows - 4.3.5



Additional Information:

The issues occurs on sfx2/source/doc/objstor.cxx:1171

try {
uno::Reference < beans::XPropertySet > xPropSet( GetStorage(), uno::UNO_QUERY_THROW );

because (DocShell *)this -> (SfxMedium *)pMedium -> (SfxMedium_Impl *)pImp -> (OStorage *)xStorage -> (OStorage_Impl *)m_pImpl is NULL
where (DocShell *) this->pImp->m_xDocStorage = pMedium->pImp->xStorage.


After some researchs, with bTryToPreserveScriptSignature = true (signed macro), this is the 2 calls of pMedium->Close(); in objstor.cxx (line 1597 and 1656) which call dispose() function of OStorage object and set pMedium->pImp->xStorage->m_pImpl to NULL.
Deleting the 2 calls fix the issues on Lubuntu and Windows but it's maybe improper to delete these Close calls.


So, I tried some cases to save the calc file to understand the issue:    breakpoint on SfxObjectShell::SaveTo_Impl


1) Save Ctrl+S (before autosave):
Enter in the section in objstor.cxx from line 1230 to 1262
Call DisconnectStorage_Impl, pMedium->pImp->bDisposeStorage is set to false.
So dispose() will be not called in pMedium->Close();.

After the save:
pImp->m_xDocStorage-> = pMedium (same)
pImp->m_xDocStorage->m_pImpl = (OStorage_Impl *) 0x2faf5f0
     
Then, no error occurs.


2) Save a copy (before autosave) or Autosave:
Enter in the section in objstor.cxx from line 1312 to 1323
No call to Disconnect so pMedium->pImp->bDisposeStorage = true
When pMedium->Close(); is called, pMedium->pImp->xStorage->m_pImpl is set to NULL.
  
After save:
pImp->m_xDocStorage-> = pMedium (same)
pImp->m_xDocStorage->m_pImpl = NULL
      
Then, error occurs on the next save.
    
    
3) Save As (before autosave):
Enter in the section in objstor.cxx from line 1312 to 1323
No call to Disconnect so pMedium->pImp->bDisposeStorage = true
When pMedium->Close(); is called, pMedium->pImp->xStorage->m_pImpl is set to NULL.
        
pImp->m_xDocStorage-> = rMedium (new SfxMedium)
pImp->m_xDocStorage->m_pImpl = NULL
        
Then, no error occurs on the next save because pMedium is replaced by the target SfxMedium.
    

I tried to make a patch adding after (line 1660) AddLog( OSL_LOG_PREFIX "SaveAs/Export" );

if ( bCopyTo )
{
    pMedium->CanDisposeStorage_Impl( false );
}

The patch works perfectly on Lubuntu but a new error occurs on Windows :
 - During a save a copy, a popup indicate that the file opened is "read only"
 - After that, on saving, an error occurs in a popup "Error saving the document. Object not accessible. The object cannot be assigned due to insufficient user right"

I don't know if this will help you but currently I don't find why an error occurs on Windows.