Backport pull request #18283 from jellyfin/release-12.z

Fix EPUB metadata and covers not loading on Windows

Original-merge: 56989b0c80

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

Backported-by: Cody Robibero <cody@robibe.ro>

tests/Jellyfin.Providers.Tests/Books/EpubUtilsTests.cs

@@ -0,0 +1,34 @@
+using System.IO;
+using System.IO.Compression;
+using System.Text;
+using MediaBrowser.Providers.Books.OpenPackagingFormat;
+using Xunit;
+
+namespace Jellyfin.Providers.Tests.Books;
+
+public class EpubUtilsTests
+{
+    [Fact]
+    public void ReadContentFilePath_ReadsRootFileFromContainer()
+    {
+        using var stream = new MemoryStream();
+        using (var archive = new ZipArchive(stream, ZipArchiveMode.Create, true))
+        {
+            using var writer = new StreamWriter(archive.CreateEntry("META-INF/container.xml").Open(), Encoding.UTF8);
+            writer.Write(
+                """
+                <?xml version="1.0"?>
+                <container version="1.0" xmlns="urn:oasis:names:tc:opendocument:xmlns:container">
+                  <rootfiles>
+                    <rootfile full-path="OEBPS/content.opf" media-type="application/oebps-package+xml"/>
+                  </rootfiles>
+                </container>
+                """);
+        }
+
+        stream.Position = 0;
+        using var epub = new ZipArchive(stream, ZipArchiveMode.Read);
+
+        Assert.Equal("OEBPS/content.opf", EpubUtils.ReadContentFilePath(epub));
+    }
+}