2 files changed, 116 insertions, 0 deletions
diff --git a/tests/Jellyfin.Controller.Tests/Drawing/ImageHelperTests.cs b/tests/Jellyfin.Controller.Tests/Drawing/ImageHelperTests.cs
new file mode 100644
index 0000000000..571cb7f0d4
--- /dev/null
+++ b/tests/Jellyfin.Controller.Tests/Drawing/ImageHelperTests.cs
@@ -0,0 +1,64 @@
+using MediaBrowser.Controller.Drawing;
+using MediaBrowser.Model.Drawing;
+using Xunit;
+
+namespace Jellyfin.Controller.Tests.Drawing;
+
+public static class ImageHelperTests
+{
+    [Fact]
+    public static void GetNewImageSize_ExplicitSizeLargerThanSource_ClampsToSource()
+    {
+        // Regression test for https://github.com/jellyfin/jellyfin/issues/17056: the caller-supplied
+        // width/height were used verbatim, so a single request could ask for a 23100x23100 encode.
+        var options = new ImageProcessingOptions { Width = 23100, Height = 23100 };
+
+        var newSize = ImageHelper.GetNewImageSize(options, new ImageDimensions(600, 336));
+
+        Assert.Equal(336, newSize.Width);
+        Assert.Equal(336, newSize.Height);
+    }
+
+    [Fact]
+    public static void GetNewImageSize_WidthLargerThanSource_ClampsToSource()
+    {
+        var options = new ImageProcessingOptions { Width = 10000 };
+
+        var newSize = ImageHelper.GetNewImageSize(options, new ImageDimensions(600, 336));
+
+        Assert.Equal(600, newSize.Width);
+        Assert.Equal(336, newSize.Height);
+    }
+
+    [Fact]
+    public static void GetNewImageSize_FillLargerThanSource_ClampsToSource()
+    {
+        // ResizeFill already refused to upscale; this pins that behaviour.
+        var options = new ImageProcessingOptions { FillWidth = 23100, FillHeight = 23100 };
+
+        var newSize = ImageHelper.GetNewImageSize(options, new ImageDimensions(600, 336));
+
+        Assert.Equal(600, newSize.Width);
+        Assert.Equal(336, newSize.Height);
+    }
+
+    [Fact]
+    public static void GetNewImageSize_SmallerThanSource_StillDownscales()
+    {
+        var options = new ImageProcessingOptions { MaxWidth = 300 };
+
+        var newSize = ImageHelper.GetNewImageSize(options, new ImageDimensions(600, 336));
+
+        Assert.Equal(300, newSize.Width);
+        Assert.Equal(168, newSize.Height);
+    }
+
+    [Fact]
+    public static void GetNewImageSize_NoSizeRequested_ReturnsSource()
+    {
+        var newSize = ImageHelper.GetNewImageSize(new ImageProcessingOptions(), new ImageDimensions(600, 336));
+
+        Assert.Equal(600, newSize.Width);
+        Assert.Equal(336, newSize.Height);
+    }
+}
diff --git a/tests/Jellyfin.Controller.Tests/Entities/BaseItemTests.cs b/tests/Jellyfin.Controller.Tests/Entities/BaseItemTests.cs
index e34eb0bda3..86bac4256a 100644
--- a/tests/Jellyfin.Controller.Tests/Entities/BaseItemTests.cs
+++ b/tests/Jellyfin.Controller.Tests/Entities/BaseItemTests.cs
@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Reflection;
+using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using Jellyfin.Database.Implementations.Entities;
@@ -27,6 +28,57 @@ namespace Jellyfin.Controller.Tests.Entities;
 
 public class BaseItemTests
 {
+    [Fact]
+    public void GetItemByNameFolderName_ShortName_IsKeptAsIs()
+    {
+        SetupPassThroughFileSystem();
+
+        Assert.Equal("Mairghread Scott", BaseItem.GetItemByNameFolderName("Mairghread Scott."));
+    }
+
+    [Fact]
+    public void GetItemByNameFolderName_OverlongName_FitsInAPathComponent()
+    {
+        SetupPassThroughFileSystem();
+
+        // What a provider result that concatenated a whole credit list into one name looks like.
+        var name = string.Join(", ", Enumerable.Repeat("Jerry Siegel (created by: Superman)", 20));
+
+        var folderName = BaseItem.GetItemByNameFolderName(name);
+
+        Assert.True(Encoding.UTF8.GetByteCount(folderName) <= 128);
+        Assert.StartsWith("Jerry Siegel (created by: Superman)", folderName, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void GetItemByNameFolderName_OverlongNamesSharingAPrefix_StayApart()
+    {
+        SetupPassThroughFileSystem();
+
+        var prefix = new string('a', 200);
+
+        Assert.NotEqual(
+            BaseItem.GetItemByNameFolderName(prefix + "Joe Shuster"),
+            BaseItem.GetItemByNameFolderName(prefix + "Bob Kane"));
+    }
+
+    [Fact]
+    public void GetItemByNameFolderName_OverlongName_IsStable()
+    {
+        SetupPassThroughFileSystem();
+
+        var name = new string('a', 300);
+
+        Assert.Equal(BaseItem.GetItemByNameFolderName(name), BaseItem.GetItemByNameFolderName(name));
+    }
+
+    private static void SetupPassThroughFileSystem()
+    {
+        var fileSystem = new Mock<IFileSystem>();
+        fileSystem.Setup(x => x.GetValidFilename(It.IsAny<string>())).Returns((string name) => name);
+        BaseItem.FileSystem = fileSystem.Object;
+    }
+
     [Theory]
     [InlineData("", "")]
     [InlineData("1", "0000000001")]