qt: fix shutdown on MacOS

src/Makefile.qt.include

@@ -145,8 +145,6 @@ QT_MOC_CPP = \
   qt/moc_favoritespage.cpp \
   qt/moc_guiutil.cpp \
   qt/moc_intro.cpp \
-  qt/moc_macdockiconhandler.cpp \
-  qt/moc_macnotificationhandler.cpp \
   qt/moc_monitoreddatamapper.cpp \
   qt/moc_noresult.cpp \
   qt/moc_notificator.cpp \
@@ -199,6 +197,12 @@ QT_MOC_CPP = \
   qt/voting/moc_votingmodel.cpp \
   qt/voting/moc_votingpage.cpp
 
+if TARGET_DARWIN
+QT_MOC_CPP += \
+  qt/moc_macdockiconhandler.cpp \
+  qt/moc_macnotificationhandler.cpp
+endif
+
 GRIDCOIN_MM = \
   qt/macdockiconhandler.mm \
   qt/macnotificationhandler.mm \

src/init.cpp

@@ -1204,7 +1204,7 @@ bool AppInit2(ThreadHandlerPtr threads)
 
     uiInterface.InitMessage(_("Loading block index..."));
     LogPrintf("Loading block index...");
-    if (!LoadBlockIndex())
+    if (!LoadBlockIndex() && !fRequestShutdown)
         return InitError(_("Error loading blkindex.dat"));
 
     // as LoadBlockIndex can take several minutes, it's possible the user

src/qt/bitcoingui.cpp

@@ -163,6 +163,8 @@ BitcoinGUI::BitcoinGUI(QWidget* parent)
 #ifdef Q_OS_MAC
     m_app_nap_inhibitor = new CAppNapInhibitor;
     m_app_nap_inhibitor->disableAppNap();
+
+    m_dock_shutdown_handler = new MacDockShutdownHandler();
 #endif
 
     // Accept D&D of URIs
@@ -239,6 +241,7 @@ BitcoinGUI::~BitcoinGUI()
         trayIcon->hide();
 #ifdef Q_OS_MAC
     delete m_app_nap_inhibitor;
+    delete m_dock_shutdown_handler;
     delete appMenuBar;
 #endif
 }

src/qt/bitcoingui.h

@@ -10,6 +10,8 @@
 
 #ifdef Q_OS_MAC
 #include <qt/macos_appnap.h>
+
+class MacDockShutdownHandler;
 #endif
 
 class TransactionTableModel;
@@ -160,6 +162,7 @@ class BitcoinGUI : public QMainWindow
 
 #ifdef Q_OS_MAC
     CAppNapInhibitor* m_app_nap_inhibitor = nullptr;
+    MacDockShutdownHandler* m_dock_shutdown_handler = nullptr;
 #endif
     // name extension to change icons according to stylesheet
     QString sSheet;

src/qt/macdockiconhandler.h

@@ -3,6 +3,8 @@
 
 #include <QMainWindow>
 #include <QObject>
+#include <objc/objc.h>
+#include <objc/message.h>
 
 QT_BEGIN_NAMESPACE
 class QIcon;
@@ -44,4 +46,11 @@ class MacDockIconHandler : public QObject
     QMainWindow *mainWindow;
 };
 
+class MacDockShutdownHandler{
+public:
+    MacDockShutdownHandler();
+
+    static int handleShutdown(id self, SEL _cmd, ...);
+};
+
 #endif // BITCOIN_QT_MACDOCKICONHANDLER_H

src/qt/macdockiconhandler.mm

@@ -8,6 +8,8 @@
 #undef slots
 #include <Cocoa/Cocoa.h>
 
+extern bool fRequestShutdown;
+
 @interface DockIconClickEventHandler : NSObject
 {
     MacDockIconHandler* dockIconHandler;
@@ -44,6 +46,23 @@ - (void)handleDockClickEvent:(NSAppleEventDescriptor*)event withReplyEvent:(NSAp
 
 @end
 
+MacDockShutdownHandler::MacDockShutdownHandler() {
+    Class delClass = (Class)[[[NSApplication sharedApplication] delegate] class];
+    SEL closeHandle = sel_registerName("applicationShouldTerminate:");
+    if (class_getInstanceMethod(delClass, closeHandle)) {
+        class_replaceMethod(delClass, closeHandle, (IMP)MacDockShutdownHandler::handleShutdown, "B@:");
+    } else {
+        class_addMethod(delClass, closeHandle, (IMP)MacDockShutdownHandler::handleShutdown,"B@:");
+    }
+}
+
+int MacDockShutdownHandler::handleShutdown(id self, SEL _cmd, ...) {
+    // Proper shutdown is possible, if MacOS does not decide to
+    // instantly send us to the shadow realm.
+    fRequestShutdown = true;
+    return false;
+}
+
 MacDockIconHandler::MacDockIconHandler() : QObject()
 {
     NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];