PaperMC/paper-server/patches/sources/net/minecraft/server/dedicated/Settings.java.patch

--- a/net/minecraft/server/dedicated/Settings.java
+++ b/net/minecraft/server/dedicated/Settings.java
@@ -20,20 +20,41 @@
 import java.util.function.Supplier;
 import java.util.function.UnaryOperator;
 import javax.annotation.Nullable;
-import net.minecraft.core.RegistryAccess;
 import org.slf4j.Logger;
 
+import joptsimple.OptionSet; // CraftBukkit
+import net.minecraft.core.RegistryAccess;
+
 public abstract class Settings<T extends Settings<T>> {
 
     private static final Logger LOGGER = LogUtils.getLogger();
     public final Properties properties;
+    private static final boolean skipComments = Boolean.getBoolean("Paper.skipServerPropertiesComments"); // Paper - allow skipping server.properties comments
+    // CraftBukkit start
+    private OptionSet options = null;
 
-    public Settings(Properties properties) {
+    public Settings(Properties properties, final OptionSet options) {
         this.properties = properties;
+
+        this.options = options;
     }
 
+    private String getOverride(String name, String value) {
+        if ((this.options != null) && (this.options.has(name))) {
+            return String.valueOf(this.options.valueOf(name));
+        }
+
+        return value;
+        // CraftBukkit end
+    }
+
     public static Properties loadFromFile(Path path) {
         try {
+            // CraftBukkit start - SPIGOT-7465, MC-264979: Don't load if file doesn't exist
+            if (!path.toFile().exists()) {
+                return new Properties();
+            }
+            // CraftBukkit end
             Properties properties;
             Properties properties1;
 
@@ -97,8 +118,53 @@
 
     public void store(Path path) {
         try {
-            BufferedWriter bufferedwriter = Files.newBufferedWriter(path, StandardCharsets.UTF_8);
+            // CraftBukkit start - Don't attempt writing to file if it's read only
+            if (path.toFile().exists() && !path.toFile().canWrite()) {
+                Settings.LOGGER.warn("Can not write to file {}, skipping.", path); // Paper - log message file is read-only
+                return;
+            }
+            // CraftBukkit end
+            // Paper start - allow skipping server.properties comments
+            java.io.OutputStream outputstream = Files.newOutputStream(path);
+            java.io.BufferedOutputStream bufferedOutputStream =  !skipComments ? new java.io.BufferedOutputStream(outputstream) : new java.io.BufferedOutputStream(outputstream) {
+                private boolean isRightAfterNewline = true; // If last written char was newline
+                private boolean isComment = false; // Are we writing comment currently?
+
+                @Override
+                public void write(@org.jetbrains.annotations.NotNull byte[] b) throws IOException {
+                    this.write(b, 0, b.length);
+                }
+
+                @Override
+                public void write(@org.jetbrains.annotations.NotNull byte[] bbuf, int off, int len) throws IOException {
+                    int latest_offset = off; // The latest offset, updated when comment ends
+                    for (int index = off; index < off + len; ++index ) {
+                        byte c = bbuf[index];
+                        boolean isNewline = (c == '\n' || c == '\r');
+                        if (isNewline && this.isComment) {
+                            // Comment has ended
+                            this.isComment = false;
+                            latest_offset = index+1;
+                        }
+                        if (c == '#' && this.isRightAfterNewline) {
+                            this.isComment = true;
+                            if (index != latest_offset) {
+                                // We got some non-comment data earlier
+                                super.write(bbuf, latest_offset, index-latest_offset);
+                            }
+                        }
+                        this.isRightAfterNewline = isNewline; // Store for next iteration
 
+                    }
+                    if (latest_offset < off+len && !this.isComment) {
+                        // We have some unwritten data, that isn't part of a comment
+                        super.write(bbuf, latest_offset, (off + len) - latest_offset);
+                    }
+                }
+            };
+            BufferedWriter bufferedwriter = new BufferedWriter(new java.io.OutputStreamWriter(bufferedOutputStream, java.nio.charset.StandardCharsets.UTF_8.newEncoder()));
+            // Paper end - allow skipping server.properties comments
+
             try {
                 this.properties.store(bufferedwriter, "Minecraft server properties");
             } catch (Throwable throwable) {
@@ -125,7 +191,7 @@
     private static <V extends Number> Function<String, V> wrapNumberDeserializer(Function<String, V> parser) {
         return (s) -> {
             try {
-                return (Number) parser.apply(s);
+                return (V) parser.apply(s); // CraftBukkit - decompile error
             } catch (NumberFormatException numberformatexception) {
                 return null;
             }
@@ -144,7 +210,7 @@
 
     @Nullable
     public String getStringRaw(String key) {
-        return (String) this.properties.get(key);
+        return (String) this.getOverride(key, this.properties.getProperty(key)); // CraftBukkit
     }
 
     @Nullable
@@ -160,10 +226,20 @@
     }
 
     protected <V> V get(String key, Function<String, V> parser, Function<V, String> stringifier, V fallback) {
-        String s1 = this.getStringRaw(key);
-        V v1 = MoreObjects.firstNonNull(s1 != null ? parser.apply(s1) : null, fallback);
+        // CraftBukkit start
+        try {
+            return this.get0(key, parser, stringifier, fallback);
+        } catch (Exception ex) {
+            throw new RuntimeException("Could not load invalidly configured property '" + key + "'", ex);
+        }
+    }
 
-        this.properties.put(key, stringifier.apply(v1));
+    private <V> V get0(String s, Function<String, V> function, Function<V, String> function1, V v0) {
+        // CraftBukkit end
+        String s1 = this.getStringRaw(s);
+        V v1 = MoreObjects.firstNonNull(s1 != null ? function.apply(s1) : null, v0);
+
+        this.properties.put(s, function1.apply(v1));
         return v1;
     }
 
@@ -172,7 +248,7 @@
         V v1 = MoreObjects.firstNonNull(s1 != null ? parser.apply(s1) : null, fallback);
 
         this.properties.put(key, stringifier.apply(v1));
-        return new Settings.MutableValue<>(key, v1, stringifier);
+        return new Settings.MutableValue(key, v1, stringifier); // CraftBukkit - decompile error
     }
 
     protected <V> V get(String key, Function<String, V> parser, UnaryOperator<V> parsedTransformer, Function<V, String> stringifier, V fallback) {
@@ -236,7 +312,7 @@
         return properties;
     }
 
-    protected abstract T reload(RegistryAccess registryManager, Properties properties);
+    protected abstract T reload(RegistryAccess iregistrycustom, Properties properties, OptionSet optionset); // CraftBukkit
 
     public class MutableValue<V> implements Supplier<V> {
 
@@ -244,7 +320,7 @@
         private final V value;
         private final Function<V, String> serializer;
 
-        MutableValue(final String s, final Object object, final Function function) {
+        MutableValue(final String s, final V object, final Function function) { // CraftBukkit - decompile error
             this.key = s;
             this.value = object;
             this.serializer = function;
@@ -258,7 +334,7 @@
             Properties properties = Settings.this.cloneProperties();
 
             properties.put(this.key, this.serializer.apply(value));
-            return Settings.this.reload(registryManager, properties);
+            return Settings.this.reload(registryManager, properties, Settings.this.options); // CraftBukkit
         }
     }
 }