Fix recursion mess in PlayerAdvancement loading, by using an alternative based on a toposorted list of all advancements.

It seems to be fully equivalent in testing, but there may be corner cases, so there is a config to disable, though disabling
may break servers, especially those chunkloading fake players.

Signed-off-by: cpw <cpw+github@weeksfamily.ca>

src/main/java/net/minecraftforge/common/AdvancementLoadFix.java

@@ -0,0 +1,104 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2019.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.common;
+
+import com.google.common.graph.Graph;
+import com.google.common.graph.GraphBuilder;
+import com.google.common.graph.MutableGraph;
+import net.minecraft.advancements.Advancement;
+import net.minecraft.advancements.AdvancementProgress;
+import net.minecraft.advancements.PlayerAdvancements;
+import net.minecraftforge.fml.loading.toposort.TopologicalSort;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.Function;
+import java.util.function.Predicate;
+import java.util.stream.Collectors;
+
+/**
+ * New implementation of {@link net.minecraft.advancements.PlayerAdvancements#ensureAllVisible()}
+ */
+public class AdvancementLoadFix {
+    private static final Logger LOGGER = LogManager.getLogger();
+    private static Map<Advancement, List<Advancement>> roots;
+
+    public static void loadVisibility(final PlayerAdvancements playerAdvancements, final Set<Advancement> visible, final Set<Advancement> visibilityChanged, final Map<Advancement, AdvancementProgress> progress, final Set<Advancement> progressChanged, final Predicate<Advancement> shouldBeVisible) {
+        LOGGER.info("Using new advancement loading for {}", playerAdvancements);
+        if (roots == null) throw new RuntimeException("Why did the advancements not load yet?!");
+        final Set<Advancement> set = new HashSet<>();
+        for(Map.Entry<Advancement, AdvancementProgress> entry : progress.entrySet()) {
+            if (entry.getValue().isDone()) {
+                set.add(entry.getKey());
+                progressChanged.add(entry.getKey());
+            }
+        }
+
+        roots.values().stream().flatMap(Collection::stream).filter(adv -> containsAncestor(adv, set)).forEach(adv->updateVisibility(adv, visible, visibilityChanged, progress, progressChanged, shouldBeVisible));
+    }
+
+    private static boolean containsAncestor(final Advancement adv, final Set<Advancement> set) {
+        return set.contains(adv) || (adv.getParent() != null && containsAncestor(adv.getParent(), set));
+    }
+
+    private static void updateVisibility(final Advancement adv, final Set<Advancement> visible, final Set<Advancement> visibilityChanged, final Map<Advancement, AdvancementProgress> progress, final Set<Advancement> progressChanged, Predicate<Advancement> shouldBeVisible) {
+        boolean flag = shouldBeVisible.test(adv);
+        boolean flag1 = visible.contains(adv);
+        if (flag && !flag1) {
+            visible.add(adv);
+            visibilityChanged.add(adv);
+            if (progress.containsKey(adv)) {
+                progressChanged.add(adv);
+            }
+        } else if (!flag && flag1) {
+            visible.remove(adv);
+            visibilityChanged.add(adv);
+        }
+        if (flag!=flag1 && adv.getParent()!=null)
+            updateVisibility(adv.getParent(), visible, visibilityChanged, progress, progressChanged, shouldBeVisible);
+    }
+
+    public static void buildSortedTrees(final Set<Advancement> roots) {
+        AdvancementLoadFix.roots = roots.stream()
+                .map(AdvancementLoadFix::buildGraph)
+                .map(g -> TopologicalSort.topologicalSort(g, Comparator.comparing(Advancement::getId)))
+                .collect(Collectors.toMap(lst -> lst.get(0), Function.identity()));
+    }
+
+    private static Graph<Advancement> buildGraph(final Advancement root) {
+        final MutableGraph<Advancement> tree = GraphBuilder.directed().build();
+        addEdgesAndChildren(root, tree);
+        return tree;
+    }
+
+    private static void addEdgesAndChildren(final Advancement root, final MutableGraph<Advancement> tree) {
+        tree.addNode(root);
+        for (Advancement adv: root.getChildren()) {
+            addEdgesAndChildren(adv, tree);
+            tree.putEdge(root, adv);
+        }
+    }
+}

src/main/java/net/minecraftforge/common/ForgeConfig.java

@@ -50,6 +50,8 @@ public class ForgeConfig
 
         public final BooleanValue treatEmptyTagsAsAir;
 
+        public final BooleanValue fixAdvancementLoading;
+
         Server(ForgeConfigSpec.Builder builder) {
             builder.comment("Server configuration settings")
                    .push("server");
@@ -110,6 +112,10 @@ public class ForgeConfig
                     .translation("forge.configgui.treatEmptyTagsAsAir")
                     .define("treatEmptyTagsAsAir", false);
 
+            fixAdvancementLoading = builder
+                    .comment("Fix advancement loading to use a proper topological sort. This may have visibility side-effects and can thus be turned off if needed for data-pack compatibility.")
+                    .translation("forge.configgui.fixAdvancementLoading")
+                    .define("fixAdvancementLoading", true);
             builder.pop();
         }
     }