From 5d3d732c25ced70e57ce840a39d9deb5d57ed88f Mon Sep 17 00:00:00 2001
From: benwoo1110 <benedict_woo_jun_kai@s2016.sst.edu.sg>
Date: Fri, 9 Oct 2020 12:19:32 +0800
Subject: [PATCH 1/2] Fix issue where special chars cause
 PatternSyntaxException

Escape regex special chars for help command
---
 .../MultiverseCore/commands/HelpCommand.java  | 20 ++++++-------------
 .../commands/PaginatedCommand.java            | 13 ++++++++++++
 2 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/src/main/java/com/onarandombox/MultiverseCore/commands/HelpCommand.java b/src/main/java/com/onarandombox/MultiverseCore/commands/HelpCommand.java
index 90913026..59a429e4 100644
--- a/src/main/java/com/onarandombox/MultiverseCore/commands/HelpCommand.java
+++ b/src/main/java/com/onarandombox/MultiverseCore/commands/HelpCommand.java
@@ -40,24 +40,16 @@ public class HelpCommand extends PaginatedCoreCommand<Command> {
 
     @Override
     protected List<Command> getFilteredItems(List<Command> availableItems, String filter) {
+        String expression = "(?i).*" + cleanFilter(filter) + ".*";
         List<Command> filtered = new ArrayList<Command>();
 
         for (Command c : availableItems) {
-            if (stitchThisString(c.getKeyStrings()).matches("(?i).*" + filter + ".*")) {
+            if (stitchThisString(c.getKeyStrings()).matches(expression)
+                    || c.getCommandName().matches(expression)
+                    || c.getCommandDesc().matches(expression)
+                    || c.getCommandUsage().matches(expression)
+                    || c.getCommandExamples().stream().anyMatch(eg -> eg.matches(expression))) {
                 filtered.add(c);
-            } else if (c.getCommandName().matches("(?i).*" + filter + ".*")) {
-                filtered.add(c);
-            } else if (c.getCommandDesc().matches("(?i).*" + filter + ".*")) {
-                filtered.add(c);
-            } else if (c.getCommandUsage().matches("(?i).*" + filter + ".*")) {
-                filtered.add(c);
-            } else {
-                for (String example : c.getCommandExamples()) {
-                    if (example.matches("(?i).*" + filter + ".*")) {
-                        filtered.add(c);
-                        break;
-                    }
-                }
             }
         }
         return filtered;
diff --git a/src/main/java/com/onarandombox/MultiverseCore/commands/PaginatedCommand.java b/src/main/java/com/onarandombox/MultiverseCore/commands/PaginatedCommand.java
index c3ddf09b..6d78cb3d 100644
--- a/src/main/java/com/onarandombox/MultiverseCore/commands/PaginatedCommand.java
+++ b/src/main/java/com/onarandombox/MultiverseCore/commands/PaginatedCommand.java
@@ -13,12 +13,14 @@ import org.bukkit.entity.Player;
 import org.bukkit.plugin.java.JavaPlugin;
 
 import java.util.List;
+import java.util.regex.Pattern;
 
 /**
  * A generic paginated command.
  * @param <T> The type of items on the page.
  */
 public abstract class PaginatedCommand<T> extends Command {
+    private final Pattern REGEX_SPECIAL_CHARS = Pattern.compile("[.+*?\\[^\\]$(){}=!<>|:-\\\\]");
     private static final int DEFAULT_ITEMS_PER_PAGE = 9;
     /**
      * The number of items per page.
@@ -40,12 +42,23 @@ public abstract class PaginatedCommand<T> extends Command {
 
     /**
      * Gets filtered items.
+     *
      * @param availableItems All available items.
      * @param filter The filter-{@link String}.
      * @return A list of items that match the filter.
      */
     protected abstract List<T> getFilteredItems(List<T> availableItems, String filter);
 
+    /**
+     * Escape regex special characters from filter
+     *
+     * @param filter The filter-{@link String}.
+     * @return String with regex characters escaped
+     */
+    protected String cleanFilter(String filter) {
+        return REGEX_SPECIAL_CHARS.matcher(filter.toLowerCase()).replaceAll("\\\\$0");
+    }
+
     /**
      * Constructs a single string from a list of strings.
      *

From 473ccd09d77a432fc9d255ea15cea285aa470fd6 Mon Sep 17 00:00:00 2001
From: Ben Woo <30431861+benwoo1110@users.noreply.github.com>
Date: Fri, 16 Jul 2021 21:38:57 +0800
Subject: [PATCH 2/2] Don't need to toLowerCase filter.

---
 .../onarandombox/MultiverseCore/commands/PaginatedCommand.java  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/java/com/onarandombox/MultiverseCore/commands/PaginatedCommand.java b/src/main/java/com/onarandombox/MultiverseCore/commands/PaginatedCommand.java
index 6d78cb3d..2dd11a2a 100644
--- a/src/main/java/com/onarandombox/MultiverseCore/commands/PaginatedCommand.java
+++ b/src/main/java/com/onarandombox/MultiverseCore/commands/PaginatedCommand.java
@@ -56,7 +56,7 @@ public abstract class PaginatedCommand<T> extends Command {
      * @return String with regex characters escaped
      */
     protected String cleanFilter(String filter) {
-        return REGEX_SPECIAL_CHARS.matcher(filter.toLowerCase()).replaceAll("\\\\$0");
+        return REGEX_SPECIAL_CHARS.matcher(filter).replaceAll("\\\\$0");
     }
 
     /**