/**
     * Creates a text merge viewer under the given parent control.
     *
     * @param parent the parent control
     * @param style SWT style bits for top level composite of this viewer
     * @param configuration the configuration object
     */
    public TextMergeViewer(Composite parent, int style, CompareConfiguration configuration) {
        
        [...]

        INavigatable nav= new INavigatable() {
            public boolean selectChange(int flag) {
                if (flag == INavigatable.FIRST_CHANGE || flag == INavigatable.LAST_CHANGE) {
                    selectFirstDiff(flag == INavigatable.FIRST_CHANGE, false);  <<--- fix
                    return false;
                }
                return navigate(flag == INavigatable.NEXT_CHANGE, false, false);
            }
            public Object getInput() {
                return TextMergeViewer.this.getInput();
            }
            public boolean openSelectedChange() {
                return false;
            }
            public boolean hasChange(int flag) {
                return getNextVisibleDiff(flag == INavigatable.NEXT_CHANGE, false) != null;
            }
        };
        fComposite.setData(INavigatable.NAVIGATOR_PROPERTY, nav);

        fBirdsEyeCursor= new Cursor(parent.getDisplay(), SWT.CURSOR_HAND);

        JFaceResources.getFontRegistry().addListener(fPreferenceChangeListener);
        JFaceResources.getColorRegistry().addListener(fPreferenceChangeListener);
        updateFont();
    }
    
    [...]

    /*
     * Initializes the text viewers of the three content areas with the given input objects.
     * Subclasses may extend.
     */
    protected void updateContent(Object ancestor, Object left, Object right) {

        [...]

        if (!fHasErrors && !emptyInput && !fComposite.isDisposed()) {
            if (isRefreshing()) {
                fLeftContributor.updateSelection(fLeft, !fSynchronizedScrolling);
                fRightContributor.updateSelection(fRight, !fSynchronizedScrolling);
                fAncestorContributor.updateSelection(fAncestor, !fSynchronizedScrolling);
                if (fSynchronizedScrolling && fSynchronziedScrollPosition != -1) {
                    synchronizedScrollVertical(fSynchronziedScrollPosition);
                }
            } else {
                if (isPatchHunk()) {
                    if (right != null && Utilities.getAdapter(right, IHunk.class) != null)
                        fLeft.setTopIndex(getHunkStart());
                    else
                        fRight.setTopIndex(getHunkStart());
                } else {
                    Diff selectDiff= null;
                    if (FIX_47640) {
                        if (leftRange != null)
                            selectDiff= findDiff(LEFT_CONTRIBUTOR, leftRange);
                        else if (rightRange != null)
                            selectDiff= findDiff(RIGHT_CONTRIBUTOR, rightRange);
                    }
                    if (selectDiff != null)
                        setCurrentDiff(selectDiff, true);
                    else
                        selectFirstDiff(true, false); <<--- fix
                }
            }
        }

    }
    
    [...]

    /*
     * Creates the two items for copying a difference range from one side to the other
     * and adds them to the given toolbar manager.
     */
    protected void createToolItems(ToolBarManager tbm) {

        [...]

        Action a= new Action() {
            public void run() {
                if (navigate(true, false, false)) {
                    endOfDocumentReached(true, false);  <<--- fix
                }
            }
        };
        Utilities.initAction(a, getResourceBundle(), "action.NextDiff."); //$NON-NLS-1$
        fNextDiff= new ActionContributionItem(a);
        tbm.appendToGroup("navigation", fNextDiff); //$NON-NLS-1$
        // Don't register this action since it is probably registered by the container

        a= new Action() {
            public void run() {
                if (navigate(false, false, false)) {
                    endOfDocumentReached(false, false);  <<--- fix
                }
            }
        };
        Utilities.initAction(a, getResourceBundle(), "action.PrevDiff."); //$NON-NLS-1$
        fPreviousDiff= new ActionContributionItem(a);
        tbm.appendToGroup("navigation", fPreviousDiff); //$NON-NLS-1$
        // Don't register this action since it is probably registered by the container

        a= new Action() {
            public void run() {
                if (navigate(true, false, true)) {
                    endOfDocumentReached(true, true);  <<--- fix
                }
            }
        };
        Utilities.initAction(a, getResourceBundle(), "action.NextChange."); //$NON-NLS-1$
        fNextChange= new ActionContributionItem(a);
        tbm.appendToGroup("navigation", fNextChange); //$NON-NLS-1$
        fHandlerService.registerAction(a, "org.eclipse.compare.selectNextChange");  //$NON-NLS-1$

        a= new Action() {
            public void run() {
                if (navigate(false, false, true)) {
                    endOfDocumentReached(false, true);  <<--- fix
                }
            }
        };
        
		[...]
    }

    /* (non-Javadoc)
     * @see org.eclipse.compare.contentmergeviewer.ContentMergeViewer#handlePropertyChangeEvent(org.eclipse.jface.util.PropertyChangeEvent)
     */
    protected void handlePropertyChangeEvent(PropertyChangeEvent event) {

        String key= event.getProperty();

        if (key.equals(CompareConfiguration.IGNORE_WHITESPACE)
                || key.equals(ComparePreferencePage.SHOW_PSEUDO_CONFLICTS)) {

            fShowPseudoConflicts= fPreferenceStore.getBoolean(ComparePreferencePage.SHOW_PSEUDO_CONFLICTS);

            update(true);
            selectFirstDiff(true, false);  <<--- fix

//      [...]

        } else {
            super.handlePropertyChangeEvent(event);

            if (key.equals(ICompareUIConstants.PROP_IGNORE_ANCESTOR)) {
                update(false);
                selectFirstDiff(true, false);  <<--- fix
            }
        }
    }

    private void selectFirstDiff(boolean first, boolean deep) {  <<--- fix

        if (fLeft == null || fRight == null) {
            return;
        }
        if (fLeft.getDocument() == null || fRight.getDocument() == null) {
            return;
        }

        Diff firstDiff= null;
        if (first)
            firstDiff= findNext(fRight, fChangeDiffs, -1, -1, deep);  <<--- fix
        else
            firstDiff= findPrev(fRight, fChangeDiffs, 9999999, 9999999, deep);  <<--- fix
        setCurrentDiff(firstDiff, true);
    }
    
    [...]

    private void endOfDocumentReached(boolean down, boolean deep) {  <<--- fix
        Control c= getControl();
        if (Utilities.okToUse(c)) {
            handleEndOfDocumentReached(c.getShell(), down, deep);  <<--- fix
        }
    }

    private void handleEndOfDocumentReached(Shell shell, boolean next, boolean deep) {  <<--- fix
        
        [...]
        
        } else {
            String message;
            String title;
            if (next) {
                title = CompareMessages.TextMergeViewer_8;
                message = CompareMessages.TextMergeViewer_9;
            } else {
                title = CompareMessages.TextMergeViewer_10;
                message = CompareMessages.TextMergeViewer_11;
            }
            if (MessageDialog.openQuestion(shell, title, message)) {
                selectFirstDiff(next, deep);  <<--- fix
            }
        }
    }

    private void performEndOfDocumentAction(Shell shell, IPreferenceStore store, String key, boolean next) {
        String value = store.getString(key);
        if (value.equals(ICompareUIConstants.PREF_VALUE_NEXT)) {
            ICompareNavigator navigator = getCompareConfiguration().getContainer().getNavigator();
            if (hasNextElement(next))
                navigator.selectChange(next);
            else
                shell.getDisplay().beep();
        } else {
            selectFirstDiff(next, false);  <<--- fix
        }
    }

	[...]

    private static Diff findNext(MergeSourceViewer tp, List v, int start, int end, boolean deep) {
        for (int i= 0; i < v.size(); i++) {
            Diff diff= (Diff) v.get(i);
            Position p= diff.getPosition(tp);
            if (p != null) {
                int startOffset= p.getOffset();
                if ((deep && end <= startOffset) || (!deep && end < startOffset)) {  <<--- fix
                    if (deep && diff.fDiffs != null) {
                        // If we are going deep, find the first change in the diff
                        return findNext(tp, diff.fDiffs, start, start, deep);
                    }
                    return diff;
                }
                if (deep && diff.fDiffs != null) {
                    Diff d= null;
                    int endOffset= startOffset + p.getLength();
                    if (start == startOffset && (end == endOffset || end == endOffset-1)) {
                        d= findNext(tp, diff.fDiffs, start-1, start-1, deep);
                    } else if (end < endOffset) {
                        d= findNext(tp, diff.fDiffs, start, end, deep);
                    }
                    if (d != null)
                        return d;
                }
            }
        }
        return null;
    }

    private static Diff findPrev(MergeSourceViewer tp, List v, int start, int end, boolean deep) {
        for (int i= v.size()-1; i >= 0; i--) {
            Diff diff= (Diff) v.get(i);
            Position p= diff.getPosition(tp);
            if (p != null) {
                int startOffset= p.getOffset();
                int endOffset= startOffset + p.getLength();
                if (start >= endOffset) {   <<--- fix
                    if (deep && diff.fDiffs != null) {
                        // If we are going deep, find the last change in the diff
                        return findPrev(tp, diff.fDiffs, end, end, deep);
                    }
                    return diff;
                }
                if (deep && diff.fDiffs != null) {
                    Diff d= null;
                    if (start == startOffset && end == endOffset) {
                        // A whole diff is selected so we'll fall through
                        // and go the the last change in the previous diff
                    } else if (start >= startOffset) {
                    	  <<--- fix
                        d= findPrev(tp, diff.fDiffs, start, end, deep);
                    }
                    if (d != null)
                        return d;
                }
            }
        }
        return null;
    }
    
    [...]

    /*
     * Copy whole document from one side to the other.
     */
    protected void copy(boolean leftToRight) {
        
		[...]
		
        update(false);
        selectFirstDiff(true, false);  <--- fix
    }
    
    [...]
}