From 2eef0f11cd9887d890a82745881397e8a641c0c4 Mon Sep 17 00:00:00 2001
From: Keith <keith@slskdn.dev>
Date: Fri, 17 Jul 2026 09:52:59 -0600
Subject: [PATCH] Preserve search filter case mode on reload

---
 docs/CHANGELOG.md                             |  2 +
 src/slskd/Application.cs                      | 38 +++++++++++--------
 .../Core/ApplicationLifecycleTests.cs         | 12 ++++++
 3 files changed, 37 insertions(+), 15 deletions(-)

diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 8860e73d9..11f53510c 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -22,6 +22,8 @@ For dev or build tags, use the same logical version string embedded in the tag.
 
 ## [Unreleased]
 
+- Reloaded search-request filters now preserve the configured regex case mode
+  instead of always becoming case-sensitive after an options change.
 - The web footer and README now offer direct PayPal and Ko-fi links for
   supporting slskdN development.
 - GitLab CI configuration now keeps the Arch package-smoke sudoers command as
diff --git a/src/slskd/Application.cs b/src/slskd/Application.cs
index ac0e94f1b..c68ca2893 100644
--- a/src/slskd/Application.cs
+++ b/src/slskd/Application.cs
@@ -186,17 +186,9 @@ public Application(
 
             Flags = Program.Flags;
 
-            var regexOptions = RegexOptions.Compiled;
-
-            if (!Flags.CaseSensitiveRegEx)
-            {
-                regexOptions |= RegexOptions.IgnoreCase;
-            }
-
-            CompiledSearchRequestFilters = OptionsAtStartup.Filters.Search.Request
-                .Select(f => new Regex(f, regexOptions, SearchRequestFilterMatchTimeout))
-                .ToList()
-                .AsReadOnly();
+            CompiledSearchRequestFilters = CompileSearchRequestFilters(
+                OptionsAtStartup.Filters.Search.Request,
+                Flags.CaseSensitiveRegEx);
 
             State = state;
             RegisterChange(State.OnChange(state => State_OnChange(state)));
@@ -782,6 +774,23 @@ internal static SoulseekClientOptionsPatch CreateStartupSoulseekClientOptionsPat
                 placeInQueueResolver: placeInQueueResolver);
         }
 
+        internal static IReadOnlyList<Regex> CompileSearchRequestFilters(
+            IEnumerable<string> filters,
+            bool caseSensitive)
+        {
+            var regexOptions = RegexOptions.Compiled;
+
+            if (!caseSensitive)
+            {
+                regexOptions |= RegexOptions.IgnoreCase;
+            }
+
+            return filters
+                .Select(f => new Regex(f, regexOptions, SearchRequestFilterMatchTimeout))
+                .ToList()
+                .AsReadOnly();
+        }
+
         private static UserEndPointCache CreateUserEndPointCache()
         {
             var cache = new UserEndPointCache();
@@ -2242,10 +2251,9 @@ static string FormatOptionLogValue(PropertyInfo? property, object? value)
                 if (PreviousOptions.Filters.Search.Request.Except(newOptions.Filters.Search.Request).Any()
                     || newOptions.Filters.Search.Request.Except(PreviousOptions.Filters.Search.Request).Any())
                 {
-                    CompiledSearchRequestFilters = newOptions.Filters.Search.Request
-                        .Select(f => new Regex(f, RegexOptions.Compiled, SearchRequestFilterMatchTimeout))
-                        .ToList()
-                        .AsReadOnly();
+                    CompiledSearchRequestFilters = CompileSearchRequestFilters(
+                        newOptions.Filters.Search.Request,
+                        Flags.CaseSensitiveRegEx);
 
                     Log.Information("Updated and re-compiled search response filters");
                 }
diff --git a/tests/slskd.Tests.Unit/Core/ApplicationLifecycleTests.cs b/tests/slskd.Tests.Unit/Core/ApplicationLifecycleTests.cs
index 8d3804085..9d25c98c0 100644
--- a/tests/slskd.Tests.Unit/Core/ApplicationLifecycleTests.cs
+++ b/tests/slskd.Tests.Unit/Core/ApplicationLifecycleTests.cs
@@ -73,6 +73,18 @@ public void CreateStartupSoulseekClientOptionsPatch_DoesNotReapplyListenerSettin
         Assert.Null(patch.ListenPort);
     }
 
+    [Theory]
+    [InlineData(false, true)]
+    [InlineData(true, false)]
+    public void CompileSearchRequestFilters_PreservesConfiguredCaseMode(
+        bool caseSensitive,
+        bool expectedMatch)
+    {
+        var filters = Application.CompileSearchRequestFilters(["^secret$"], caseSensitive);
+
+        Assert.Equal(expectedMatch, filters[0].IsMatch("SECRET"));
+    }
+
     [Fact]
     public void FormatCompletedTransferProgress_ClampsNegativeAverageSpeed()
     {