Backport pull request #15746 from jellyfin/release-10.11.z

Skip invalid ignore rules

Original-merge: 6e60634c9f

Merged-by: crobibero <cody@robibe.ro>

Backported-by: Bond_009 <bond.009@outlook.com>

Emby.Server.Implementations/Library/DotIgnoreIgnoreRule.cs

@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using System.Text.RegularExpressions;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.IO;
 using MediaBrowser.Controller.Resolvers;
@@ -70,12 +71,55 @@ public class DotIgnoreIgnoreRule : IResolverIgnoreRule
     {
         // If file has content, base ignoring off the content .gitignore-style rules
         var rules = ignoreFileContent.Split('\n', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+        return CheckIgnoreRules(path, rules, isDirectory);
+    }
+
+    /// <summary>
+    /// Checks whether a path should be ignored based on an array of ignore rules.
+    /// </summary>
+    /// <param name="path">The path to check.</param>
+    /// <param name="rules">The array of ignore rules.</param>
+    /// <param name="isDirectory">Whether the path is a directory.</param>
+    /// <returns>True if the path should be ignored.</returns>
+    internal static bool CheckIgnoreRules(string path, string[] rules, bool isDirectory)
+        => CheckIgnoreRules(path, rules, isDirectory, IsWindows);
+
+    /// <summary>
+    /// Checks whether a path should be ignored based on an array of ignore rules.
+    /// </summary>
+    /// <param name="path">The path to check.</param>
+    /// <param name="rules">The array of ignore rules.</param>
+    /// <param name="isDirectory">Whether the path is a directory.</param>
+    /// <param name="normalizePath">Whether to normalize backslashes to forward slashes (for Windows paths).</param>
+    /// <returns>True if the path should be ignored.</returns>
+    internal static bool CheckIgnoreRules(string path, string[] rules, bool isDirectory, bool normalizePath)
+    {
         var ignore = new Ignore.Ignore();
-        ignore.Add(rules);
+
+        // Add each rule individually to catch and skip invalid patterns
+        var validRulesAdded = 0;
+        foreach (var rule in rules)
+        {
+            try
+            {
+                ignore.Add(rule);
+                validRulesAdded++;
+            }
+            catch (RegexParseException)
+            {
+                // Ignore invalid patterns
+            }
+        }
+
+        // If no valid rules were added, fall back to ignoring everything (like an empty .ignore file)
+        if (validRulesAdded == 0)
+        {
+            return true;
+        }
 
          // Mitigate the problem of the Ignore library not handling Windows paths correctly.
          // See https://github.com/jellyfin/jellyfin/issues/15484
-        var pathToCheck = IsWindows ? path.NormalizePath('/') : path;
+        var pathToCheck = normalizePath ? path.NormalizePath('/') : path;
 
         // Add trailing slash for directories to match "folder/"
         if (isDirectory)