Fix Hanging When No Valid Spawn Point Exists

docs/CHANGELOG.md

@@ -57,6 +57,7 @@
     * `Text Rendering Fixes` (Enabled By Default)
     * `Close Editor When Sign Is Destroyed` (Enabled By Default)
     * `Remove Chest Placement Restrictions` (Enabled By Default)
+    * `Fix Hanging When No Valid Spawn Point Exists` (Enabled By Default)
   * Existing Functionality (All Enabled By Default)
     * `Fix Screen Rendering When Hiding HUD`
     * `Sanitize Usernames`

libreborn/src/util/env/flags/available-feature-flags

@@ -135,6 +135,7 @@ CATEGORY Bug Fixes
         TRUE Close Current Screen On Death
     TRUE Fix Reloading Textures On Resize
     TRUE Fix options.txt Loading/Saving
+    TRUE Fix Hanging When No Valid Spawn Point Exists
 CATEGORY Logging
     FALSE Log FPS
     TRUE Log Chat Messages

mods/src/misc/misc.cpp

@@ -468,6 +468,31 @@ static SignTileEntity *SignTileEntity_destructor_injection(SignTileEntity_destru
     return original(self);
 }
 
+// Fix Spawn Point Hanging
+static constexpr int allowed_spawn_point_tries = 10000;
+static constexpr int not_finding_spawn_point = -1;
+static int spawn_point_tries = not_finding_spawn_point;
+static void Level_setInitialSpawn_or_validateSpawn_injection(Level_setInitialSpawn_t original, Level *self) {
+    spawn_point_tries = allowed_spawn_point_tries;
+    original(self);
+    spawn_point_tries = not_finding_spawn_point;
+}
+static int Level_getTopTile_injection(Level_getTopTile_t original, Level *self, int x, int z) {
+    bool actually_check = true;
+    if (spawn_point_tries == 0) {
+        // Give Up Searching
+        actually_check = false;
+    } else if (spawn_point_tries > 0) {
+        // Count Down
+        spawn_point_tries--;
+    }
+    if (actually_check) {
+        return original(self, x, z);
+    } else {
+        return Tile::bedrock->id;
+    }
+}
+
 // Init
 void init_misc() {
     // Sanitize Username
@@ -636,6 +661,13 @@ void init_misc() {
         overwrite_calls(SignTileEntity_destructor_complete, SignTileEntity_destructor_injection);
     }
 
+    // Fix Hanging When Spawning
+    if (feature_has("Fix Hanging When No Valid Spawn Point Exists", server_enabled)) {
+        overwrite_calls(Level_setInitialSpawn, Level_setInitialSpawn_or_validateSpawn_injection);
+        overwrite_calls(Level_validateSpawn, Level_setInitialSpawn_or_validateSpawn_injection);
+        overwrite_calls(Level_getTopTile, Level_getTopTile_injection);
+    }
+
     // Disable overwrite_calls() After Minecraft::init
     misc_run_on_init([](__attribute__((unused)) Minecraft *minecraft) {
         thunk_enabler = [](__attribute__((unused)) void *a, __attribute__((unused)) void *b) -> void * {

symbols/src/level/Level.def

@@ -51,6 +51,8 @@ method bool canSeeSky(int x, int y, int z) = 0xa39b8;
 method bool isDay() = 0xa3d9c;
 method int getTopTile(int x, int z) = 0xa2cc8;
 method BiomeSource *getBiomeSource() = 0xa3c64;
+method void setInitialSpawn() = 0xa2bf4;
+method void validateSpawn() = 0xa2d2c;
 
 virtual-method void tick() = 0x28;
 virtual-method void updateSleepingPlayerList() = 0x2c;