Reject undefined numeric LogLevel values (#390)

src/SharpEmu.Logging/SharpEmuLog.cs

@@ -110,7 +110,8 @@ public static class SharpEmuLog
         }
 
         var normalized = text.Trim();
-        if (Enum.TryParse<LogLevel>(normalized, ignoreCase: true, out level))
+        if (Enum.TryParse<LogLevel>(normalized, ignoreCase: true, out level) &&
+            Enum.IsDefined(level))
         {
             return true;
         }
@@ -127,6 +128,7 @@ public static class SharpEmuLog
             return true;
         }
 
+        level = default;
         return false;
     }
 

tests/SharpEmu.Libs.Tests/Logging/SharpEmuLogTests.cs

@@ -0,0 +1,39 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using SharpEmu.Logging;
+using Xunit;
+
+namespace SharpEmu.Libs.Tests.Logging;
+
+public sealed class SharpEmuLogTests
+{
+    [Theory]
+    [InlineData("Trace", LogLevel.Trace)]
+    [InlineData("debug", LogLevel.Debug)]
+    [InlineData(" Info ", LogLevel.Info)]
+    [InlineData("WARNING", LogLevel.Warning)]
+    [InlineData("Error", LogLevel.Error)]
+    [InlineData("critical", LogLevel.Critical)]
+    [InlineData("None", LogLevel.None)]
+    [InlineData("warn", LogLevel.Warning)]
+    [InlineData("fatal", LogLevel.Critical)]
+    public void TryParseLevelAcceptsDefinedNamesAndAliases(string text, LogLevel expected)
+    {
+        Assert.True(SharpEmuLog.TryParseLevel(text, out var actual));
+        Assert.Equal(expected, actual);
+    }
+
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData("   ")]
+    [InlineData("unknown")]
+    [InlineData("999")]
+    [InlineData("-1")]
+    public void TryParseLevelRejectsInvalidValues(string? text)
+    {
+        Assert.False(SharpEmuLog.TryParseLevel(text, out var level));
+        Assert.Equal(default, level);
+    }
+}