Description Michael Scharf 2004-06-01 22:03:37 EDT

We ran into a problem with AbstractTextEditor.doSetInput
which temporarily references an unconnected document when
reusing an editor. With standard GapTextStore based document
implementations this does not make a big difference, but we
use a temporary scratchfile as text storage, which is
disposed when the documents refcount reaches 0. Thus the
document is no longer usable, then.

The problem did not exist in eclipse 2.1.2. In eclispe 3.0M9,
4 lines of code (2727-2730) have been added:

    protected void doSetInput(IEditorInput input) throws CoreException { [...]
        provider.connect(input);
        
        initializeTitle(input);

+       if (fIsOverwriting)
+           toggleOverwriteMode();
+       setInsertMode((InsertMode) getLegalInsertModes().get(0));
+       updateCaret();
        
        if (fSourceViewer != null)
            initializeSourceViewer(input);
            
        updateStatusField
(ITextEditorActionConstants.STATUS_CATEGORY_ELEMENT_STATE);


When updating the caret (triggered by setInsertMode),
StyledText still references the disconnected document, only
after initializeSourceViewer(input) it is updated to the new
document.  Probably the problem vanishes, if the 4 lines
would be moved after initializeSourceViewer(input).

We also identified a similar bug in
AbstractTextEditor.ElementStateListener.elementMoved:

    public void elementMoved(final Object originalElement, final Object 
movedElement) { [...]
      	IDocumentProvider d= getDocumentProvider();
      	IDocument changed= null;
      	if (isDirty())
      	    changed= d.getDocument(getEditorInput());
      	    
      	setInput((IEditorInput) movedElement);
      	            
      	if (changed != null) {
!     	    d.getDocument(getEditorInput()).set(changed.get());
      	    validateState(getEditorInput());
      	    updateStatusField
(ITextEditorActionConstants.STATUS_CATEGORY_ELEMENT_STATE);
      	}                   

setInput disconnects the old document (changed), which is
referenced a few lines later.  The content of "changed"
could be saved to a local String variable before setting the
new input.