Implement check for tabs in config-file. Fixes resets.

This commit creates a fail-fast exception-throwing guard inside the
method for handling config-reloading in the main plugin class.

If a config-file contains a tab, an exception will be thrown when
the plugin loads (as it did before), which means the plugin will not
load correctly. However, upon reloading with the reload command, an
exception is thrown before the current settings are overwritten.

This fixes a long-standing issue with config-files resetting upon
reload with invalid syntax. Verification is needed, as this commit
has only been tested on OS X where tabs and carriage returns are
injected via vim.

src/com/garbagemule/MobArena/ArenaMasterImpl.java

@@ -633,7 +633,7 @@ public class ArenaMasterImpl implements ArenaMaster
         for (Arena a : arenas) {
             a.forceEnd();
         }
-        plugin.reloadConfig();
+        plugin.reloadConfigFile();
         config = plugin.getConfig();
         initialize();
         if (wasEnabled) setEnabled(true);

src/com/garbagemule/MobArena/MobArena.java

@@ -1,6 +1,6 @@
 package com.garbagemule.MobArena;
 
-import java.io.File;
+import java.io.*;
 import java.util.HashSet;
 import java.util.Random;
 import java.util.Set;
@@ -52,7 +52,7 @@ public class MobArena extends JavaPlugin
 
     public void onEnable() {
         // Initialize config-file
-        loadConfigFile();
+        reloadConfigFile();
 
         // Initialize announcements-file
         loadAnnouncementsFile();
@@ -102,9 +102,49 @@ public class MobArena extends JavaPlugin
         return getFile();
     }
     
-    private void loadConfigFile() {
-        // Create if missing
+    void reloadConfigFile() {
+        // Check for tab characters in config-file
+        BufferedReader in = null;
+        try {
+            in = new BufferedReader(new FileReader(new File(getDataFolder(), "config.yml")));
+            int row = 0;
+            String line;
+            while ((line = in.readLine()) != null) {
+                row++;
+                if (line.indexOf('\t') != -1) {
+                    StringBuilder buffy = new StringBuilder();
+                    buffy.append("Found tab in config-file on line ").append(row).append(".");
+                    buffy.append('\n').append("NEVER use tabs! ALWAYS use spaces!");
+                    buffy.append('\n').append(line);
+                    buffy.append('\n');
+                    for (int i = 0; i < line.indexOf('\t'); i++) {
+                        buffy.append(' ');
+                    }
+                    buffy.append('^');
+                    throw new IllegalArgumentException(buffy.toString());
+                }
+            }
+
+            // Actually reload the config-file
+            reloadConfig();
+        } catch (FileNotFoundException e) {
+            // If the config-file doesn't exist, create the default
+            Messenger.info("No config-file found, creating default...");
             saveDefaultConfig();
+        } catch (IOException e) {
+            // Error reading the file, just re-throw
+            Messenger.severe("There was an error reading the config-file.");
+            throw new RuntimeException(e);
+        } finally {
+            // Java 6 <3
+            if (in != null) {
+                try {
+                    in.close();
+                } catch (IOException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
 
         // Set the header and save
         getConfig().options().header(getHeader());

src/com/garbagemule/MobArena/commands/setup/ConfigCommand.java

@@ -1,5 +1,6 @@
 package com.garbagemule.MobArena.commands.setup;
 
+import org.bukkit.ChatColor;
 import org.bukkit.command.CommandSender;
 
 import com.garbagemule.MobArena.*;
@@ -21,8 +22,14 @@ public class ConfigCommand implements Command
         if (args.length != 1) return false;
 
         if (args[0].equals("reload")) {
+            try {
                 am.reloadConfig();
                 Messenger.tell(sender, "Config reloaded.");
+            } catch (Exception e) {
+                Messenger.tell(sender, ChatColor.RED + "ERROR:" + ChatColor.RESET + "\n" + e.getMessage());
+                Messenger.tell(sender, "MobArena has been " + ChatColor.RED + "disabled" + ChatColor.RESET + ".");
+                Messenger.tell(sender, "Fix the config-file, then reload it again, and then type " + ChatColor.YELLOW + "/ma enable" + ChatColor.RESET + " to re-enable MobArena.");
+            }
         } else if (args[0].equals("save")) {
             am.saveConfig();
             Messenger.tell(sender, "Config saved.");