Fix early client lifecyle events and introduce ClientResourceLoadFinishedEvent. The NeoForge event bus also starts earlier now.

patches/net/minecraft/client/Minecraft.java.patch

@@ -90,6 +90,14 @@
                          this.selfTest();
                      }
 
+@@ -668,6 +_,7 @@
+     }
+
+     private void onResourceLoadFinished(@Nullable Minecraft.GameLoadCookie p_299896_) {
++        net.neoforged.neoforge.client.ClientHooks.fireResourceLoadFinishedEvent(!this.gameLoadFinished);
+         if (!this.gameLoadFinished) {
+             this.gameLoadFinished = true;
+             this.onGameLoadFinished(p_299896_);
 @@ -704,6 +_,8 @@
              runnable = () -> this.setScreen(screen);
          }
@@ -311,11 +319,13 @@
                      if (!itemstack.isEmpty()
                          && this.gameMode.useItem(this.player, interactionhand) instanceof InteractionResult.Success interactionresult$success1) {
                          if (interactionresult$success1.swingSource() == InteractionResult.SwingSource.CLIENT) {
-@@ -1675,6 +_,8 @@
+@@ -1675,6 +_,10 @@
 
      public void tick() {
          this.clientTickCount++;
-+        net.neoforged.neoforge.client.ClientHooks.fireClientTickPre();
++        if (this.gameLoadFinished) {
++            net.neoforged.neoforge.client.ClientHooks.fireClientTickPre();
++        }
 +
          if (this.level != null && !this.pause) {
              this.level.tickRateManager().tick();
@@ -336,12 +346,14 @@
              }
 
              profilerfiller.popPush("animateTick");
-@@ -1810,6 +_,8 @@
+@@ -1810,6 +_,10 @@
          profilerfiller.popPush("keyboard");
          this.keyboardHandler.tick();
          profilerfiller.pop();
 +
-+        net.neoforged.neoforge.client.ClientHooks.fireClientTickPost();
++        if (this.gameLoadFinished) {
++            net.neoforged.neoforge.client.ClientHooks.fireClientTickPost();
++        }
      }
 
      private boolean isLevelRunningNormally() {

src/client/java/net/neoforged/neoforge/client/ClientHooks.java

@@ -150,6 +150,7 @@
 import net.neoforged.neoforge.client.event.ClientPauseChangeEvent;
 import net.neoforged.neoforge.client.event.ClientPlayerChangeGameTypeEvent;
 import net.neoforged.neoforge.client.event.ClientPlayerNetworkEvent;
+import net.neoforged.neoforge.client.event.ClientResourceLoadFinishedEvent;
 import net.neoforged.neoforge.client.event.ClientTickEvent;
 import net.neoforged.neoforge.client.event.ComputeFovModifierEvent;
 import net.neoforged.neoforge.client.event.ConfigureMainRenderTargetEvent;
@@ -1052,6 +1053,13 @@ public static void fireRenderFramePost(DeltaTracker partialTick) {
         RenderSystem.ensurePipelineModifiersEmpty();
     }
 
+    /**
+     * Fires {@link ClientResourceLoadFinishedEvent}.
+     */
+    public static void fireResourceLoadFinishedEvent(boolean initial) {
+        NeoForge.EVENT_BUS.post(new ClientResourceLoadFinishedEvent(initial));
+    }
+
     /**
      * Fires {@link ClientTickEvent.Pre}. Called from the head of {@link Minecraft#tick()}.
      */

src/client/java/net/neoforged/neoforge/client/event/ClientResourceLoadFinishedEvent.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) NeoForged and contributors
+ * SPDX-License-Identifier: LGPL-2.1-only
+ */
+
+package net.neoforged.neoforge.client.event;
+
+import net.neoforged.bus.api.Event;
+
+/**
+ * Fires after the client has completed loading or reloading its resources
+ * successfully.
+ * <p>
+ * When the client first starts up, this event is fired after the resource
+ * load, but before the client has set up the initial screens, and before
+ * we emit the first {@link ClientTickEvent}.
+ */
+public class ClientResourceLoadFinishedEvent extends Event {
+    private final boolean initial;
+
+    public ClientResourceLoadFinishedEvent(boolean initial) {
+        this.initial = initial;
+    }
+
+    /**
+     * @return True if the reload that completed was the initial resource load of the client.
+     */
+    public boolean isInitial() {
+        return initial;
+    }
+}

src/client/java/net/neoforged/neoforge/client/event/ClientTickEvent.java

@@ -11,6 +11,8 @@
  * Base class of the two client tick events.
  * <p>
  * For the event that fires once per frame (instead of per tick), see {@link RenderFrameEvent}.
+ * <p>
+ * Note that tick events will only start being emitted once the first {@link ClientResourceLoadFinishedEvent resource reload has completed}.
  * 
  * @see ClientTickEvent.Pre
  * @see ClientTickEvent.Post

src/client/java/net/neoforged/neoforge/client/loading/ClientModLoader.java

@@ -26,7 +26,6 @@
 import net.neoforged.fml.loading.EarlyLoadingScreenController;
 import net.neoforged.neoforge.client.config.NeoForgeClientConfig;
 import net.neoforged.neoforge.client.gui.LoadingErrorScreen;
-import net.neoforged.neoforge.common.NeoForge;
 import net.neoforged.neoforge.internal.CommonModLoader;
 import net.neoforged.neoforge.logging.CrashReportExtender;
 import net.neoforged.neoforge.resource.ResourcePackLoader;
@@ -128,9 +127,6 @@ public static Runnable completeModLoading(Runnable initialScreensTask) {
             return () -> Minecraft.getInstance().setScreen(new LoadingErrorScreen(error.getIssues(), dumpedLocation, () -> {}));
         }
 
-        // We can finally start the game eventbus up
-        NeoForge.EVENT_BUS.start();
-
         if (!warnings.isEmpty()) {
             if (showWarnings) {
                 return () -> Minecraft.getInstance().setScreen(new LoadingErrorScreen(warnings, null, initialScreensTask));

src/main/java/net/neoforged/neoforge/internal/CommonModLoader.java

@@ -20,6 +20,7 @@
 import net.neoforged.fml.event.lifecycle.InterModProcessEvent;
 import net.neoforged.fml.loading.FMLEnvironment;
 import net.neoforged.fml.loading.FMLPaths;
+import net.neoforged.neoforge.common.NeoForge;
 import net.neoforged.neoforge.network.registration.NetworkRegistry;
 import net.neoforged.neoforge.registries.GameData;
 import net.neoforged.neoforge.registries.RegistryManager;
@@ -63,6 +64,8 @@ protected static void begin(Runnable periodicTask, boolean datagen) {
                 ConfigTracker.INSTANCE.loadConfigs(ModConfig.Type.COMMON, FMLPaths.CONFIGDIR.get());
             });
         }
+
+        NeoForge.EVENT_BUS.start();
     }
 
     protected static void load(Executor syncExecutor, Executor parallelExecutor) {

src/main/java/net/neoforged/neoforge/server/loading/ServerModLoader.java

@@ -11,7 +11,6 @@
 import net.neoforged.fml.ModLoadingException;
 import net.neoforged.fml.ModLoadingIssue;
 import net.neoforged.fml.ModWorkManager;
-import net.neoforged.neoforge.common.NeoForge;
 import net.neoforged.neoforge.internal.CommonModLoader;
 import net.neoforged.neoforge.logging.CrashReportExtender;
 import net.neoforged.neoforge.server.LanguageHook;
@@ -44,7 +43,6 @@ public static void load() {
                 LOGGER.warn(Logging.LOADING, "{} [{}]", issue.translationKey(), issue.translationArgs());
             }
         }
-        NeoForge.EVENT_BUS.start();
     }
 
     public static boolean hasErrors() {