chatgui: add diagnostic logging for Windows emoji animation bug investigation

tools/chatgui/src/messagelist.cpp

@@ -16,6 +16,7 @@
 #include <QScrollBar>
 #include <QApplication>
 #include <QDebug>
+#include <cstdio>
 #include <vector>
 #include <memory>
 
@@ -104,11 +105,18 @@ MessageList::MessageList(DbManager* db, QWidget *parent)
                 if (e.type == EmojiType::Animation && !e.animPath.isEmpty()) {
                     QFile f(e.animPath);
                     if (f.open(QIODevice::ReadOnly)) {
-                        auto icon = std::make_unique<LottieIcon>(f.readAll());
+                        QByteArray raw = f.readAll();
+                        auto icon = std::make_unique<LottieIcon>(raw);
+                        fprintf(stderr, "[DIAG register] path=%s fileOpen=1 rawSize=%d iconPtr=%p iconValid=%d\n",
+                                qPrintable(e.animPath), (int)raw.size(),
+                                (void*)icon.get(), (int)icon->isValid());
                         if (icon->isValid()) {
                             AnimTimer::instance()->registerIcon(e.animPath, icon.get());
                             s_icons.push_back(std::move(icon));
                         }
+                    } else {
+                        fprintf(stderr, "[DIAG register] path=%s fileOpen=0\n",
+                                qPrintable(e.animPath));
                     }
                 }
             }