Bug 79855 [IDE] isCompatibleVersion method in IDEApplication appears wrong...
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/IDEApplication.java
* existing file contents. Writing the version file isn't really crucial,
     * so the function is silent about failure
     */
    private static void writeWorkspaceVersion() {
        Location instanceLoc = Platform.getInstanceLocation();
        if (instanceLoc == null || instanceLoc.isReadOnly())
            return;
        File versionFile = getVersionFile(instanceLoc.getURL(), true);
        if (versionFile == null)
            return;
        OutputStream output = null;
        try {
            String versionLine = WORKSPACE_VERSION_KEY + '='
                    + WORKSPACE_VERSION_VALUE;
            output = new FileOutputStream(versionFile);
            output.write(versionLine.getBytes("UTF-8")); 
        } catch (IOException e) {
            IDEWorkbenchPlugin.log("Could not write version file", 
                    StatusUtil.newStatus(IStatus.ERROR, e.getMessage(), e));
        } finally {
            try {
                if (output != null)
                    output.close();
            } catch (IOException e) {
                
            }
        }
    }
    /**
     * The version file is stored in the metadata area of the workspace. This