Fix problem deleting app::Document that are inside a Context

src/app/app.cpp

@@ -260,8 +260,23 @@ int App::run()
 
     // Destroy all documents in the UIContext.
     const doc::Documents& docs = m_modules->m_ui_context.documents();
-    while (!docs.empty())
-      delete docs.back();
+    while (!docs.empty()) {
+      doc::Document* doc = docs.back();
+
+      // First we close the document. In this way we receive recent
+      // notifications related to the document as an app::Document. If
+      // we delete the document directly, we destroy the app::Document
+      // too early, and then doc::~Document() call
+      // DocumentsObserver::onRemoveDocument(). In this way, observers
+      // could think that they have a fully created app::Document when
+      // in reality it's a doc::Document (in the middle of a
+      // destruction process).
+      //
+      // TODO: This problem is because we're extending doc::Document,
+      // in the future, we should remove app::Document.
+      doc->close();
+      delete doc;
+    }
 
     // Destroy the window.
     m_mainWindow.reset(NULL);

src/app/document.cpp

@@ -75,6 +75,13 @@ Document::Document(Sprite* sprite)
 
 Document::~Document()
 {
+  // We cannot be in a context at this moment. If we were in a
+  // context, doc::~Document() would remove the document from the
+  // context and it would generate onRemoveDocument() notifications,
+  // which could result in serious problems for observers expecting a
+  // fully created app::Document.
+  ASSERT(context() == NULL);
+
   if (m_bound.seg)
     base_free(m_bound.seg);