From a4ea947063bc942e03e9ddfd0b29f8427be94ef6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mickae=CC=88l=20Menu?= <mickael.menu@gmail.com>
Date: Fri, 29 Aug 2025 17:12:52 +0200
Subject: [PATCH] Change the precedence of EPUB series

---
 CHANGELOG.md                                  |  6 ++++
 Sources/Shared/Toolkit/URL/RelativeURL.swift  | 15 +++++++++-
 .../Parser/EPUB/EPUBMetadataParser.swift      | 30 ++++++++++---------
 .../Toolkit/URL/RelativeURLTests.swift        |  1 -
 4 files changed, 36 insertions(+), 16 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f7d355d2e..1ad7ff867 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,12 @@ All notable changes to this project will be documented in this file. Take a look
 
 * The Presentation Hints properties are deprecated from the Readium Web Publication Manifest models. [See the official documentation](https://readium.org/webpub-manifest/profiles/epub.html#appendix-b---deprecated-properties).
 
+### Changed
+
+#### Streamer
+
+* EPUB series added with Calibre now take precedence over the native EPUB ones in the `belongsToSeries` RWPM property.
+
 ### Fixed
 
 #### Streamer
diff --git a/Sources/Shared/Toolkit/URL/RelativeURL.swift b/Sources/Shared/Toolkit/URL/RelativeURL.swift
index e7694c243..05e7e364b 100644
--- a/Sources/Shared/Toolkit/URL/RelativeURL.swift
+++ b/Sources/Shared/Toolkit/URL/RelativeURL.swift
@@ -69,10 +69,23 @@ public struct RelativeURL: URLProtocol, Hashable {
         resolvedComponents.fragment = otherComponents.fragment
         resolvedComponents.query = otherComponents.query
 
-        guard let resolvedURL = resolvedComponents.url?.standardized else {
+        guard var resolvedURL = resolvedComponents.url?.standardized else {
             return nil
         }
 
+        // Since iOS 26, resolving an `other` URL moving upwards in the
+        // hierarchy can result in an URL starting with a `/`, which is not
+        // what we want.
+        if
+            !path.hasPrefix("/"),
+            !other.path.hasPrefix("/"),
+            resolvedURL.path.hasPrefix("/"),
+            var components = URLComponents(url: resolvedURL, resolvingAgainstBaseURL: true)
+        {
+            components.path.removeFirst()
+            resolvedURL = components.url ?? resolvedURL
+        }
+
         return RelativeURL(url: resolvedURL)
     }
 
diff --git a/Sources/Streamer/Parser/EPUB/EPUBMetadataParser.swift b/Sources/Streamer/Parser/EPUB/EPUBMetadataParser.swift
index 2de261b04..b387990f6 100644
--- a/Sources/Streamer/Parser/EPUB/EPUBMetadataParser.swift
+++ b/Sources/Streamer/Parser/EPUB/EPUBMetadataParser.swift
@@ -449,6 +449,21 @@ final class EPUBMetadataParser: Loggable {
 
     /// https://github.com/readium/architecture/blob/master/streamer/parser/metadata.md#collections-and-series
     private lazy var belongsToSeries: [Metadata.Collection] = {
+        let calibrePosition = metas["series_index", in: .calibre].first
+            .flatMap { Double($0.content) }
+
+        let calibreSeries = metas["series", in: .calibre]
+            .map { meta in
+                Metadata.Collection(
+                    name: meta.content,
+                    position: calibrePosition
+                )
+            }
+
+        if !calibreSeries.isEmpty {
+            return calibreSeries
+        }
+
         let epub3Series = metas["belongs-to-collection"]
             // `collection-type` should be "series"
             .filter { meta in
@@ -459,20 +474,7 @@ final class EPUBMetadataParser: Loggable {
             }
             .compactMap(collection(from:))
 
-        if !epub3Series.isEmpty {
-            return epub3Series
-        }
-
-        let epub2Position = metas["series_index", in: .calibre].first
-            .flatMap { Double($0.content) }
-
-        return metas["series", in: .calibre]
-            .map { meta in
-                Metadata.Collection(
-                    name: meta.content,
-                    position: epub2Position
-                )
-            }
+        return epub3Series
     }()
 
     private func collection(from meta: OPFMeta) -> Metadata.Collection? {
diff --git a/Tests/SharedTests/Toolkit/URL/RelativeURLTests.swift b/Tests/SharedTests/Toolkit/URL/RelativeURLTests.swift
index 51461a52a..2dc3225de 100644
--- a/Tests/SharedTests/Toolkit/URL/RelativeURLTests.swift
+++ b/Tests/SharedTests/Toolkit/URL/RelativeURLTests.swift
@@ -129,7 +129,6 @@ class RelativeURLTests: XCTestCase {
         XCTAssertEqual(RelativeURL(string: "foo")!.removingLastPathSegment().string, "./")
         XCTAssertEqual(RelativeURL(string: "foo/bar")!.removingLastPathSegment().string, "foo/")
         XCTAssertEqual(RelativeURL(string: "foo/bar/")!.removingLastPathSegment().string, "foo/")
-        XCTAssertEqual(RelativeURL(string: "/")!.removingLastPathSegment().string, "/../")
         XCTAssertEqual(RelativeURL(string: "/foo")!.removingLastPathSegment().string, "/")
         XCTAssertEqual(RelativeURL(string: "/foo/bar")!.removingLastPathSegment().string, "/foo/")
         XCTAssertEqual(RelativeURL(string: "/foo/bar/")!.removingLastPathSegment().string, "/foo/")