fix: CurseForge 无法正常下载文件

ZalithLauncher/src/main/java/com/movtery/zalithlauncher/game/download/engine/FileDownloader.kt

@@ -244,9 +244,10 @@ class FileDownloader(
         apply { initCause(cause) }
 
     private fun executeSegment(source: SourceSet.Source, segment: SegmentChain.Segment, chain: SegmentChain, channel: FileChannel) {
-        val rangeFrom = segment.position()
+        //部分 CDN 的鉴权层会拒绝任何携带 Range 的请求，从零开始的段必须以普通 GET 起步
+        val rangeFrom = segment.position().takeIf { it > 0L } ?: -1L
         executeCall(source.url, rangeFrom).use { response ->
-            val body = checkStatus(response, rangeFrom, rangedRequest = true, source = source, chain = chain)
+            val body = checkStatus(response, rangeFrom, rangedRequest = rangeFrom >= 0, source = source, chain = chain)
             streamInto(body.byteStream(), segment, chain, channel)
         }
     }

ZalithLauncher/src/main/java/com/movtery/zalithlauncher/path/UrlManager.kt

@@ -46,7 +46,7 @@ val TIME_OUT = TimeUnit.SECONDS.toMillis(30L)
 const val SMALL_FILE_READ_TIMEOUT_MS = 5_000L
 
 const val HOST_CURSEFORGE_API = "api.curseforge.com"
-const val HOST_CURSEFORGE_EDGE = "edge.forgecdn.net"
+const val CURSEFORGE_CDN_SUFFIX = "forgecdn.net"
 
 const val URL_MCMOD: String = "https://www.mcmod.cn/"
 const val URL_MINECRAFT_VERSION_REPOS: String = "https://piston-meta.mojang.com/mc/game/version_manifest_v2.json"
@@ -67,16 +67,20 @@ const val URL_CLOUD_RENDERER_PLUGINS = "https://www.123865.com/s/YLIUVv-hae0v"
 const val URL_CLOUD_DRIVE_DRIVER_PLUGINS = "https://www.123865.com/s/YLIUVv-3ae0v"
 const val URL_CLOUD_NATIVE_LIB_PLUGINS = "https://www.123865.com/s/YLIUVv-Hae0v"
 
+private fun isCurseForgeHost(host: String): Boolean =
+    host == HOST_CURSEFORGE_API ||
+            host == CURSEFORGE_CDN_SUFFIX ||
+            host.endsWith(".$CURSEFORGE_CDN_SUFFIX")
+
 /**
  * An [Interceptor] for CurseForge API requests.
  *
- * It automatically injects the `x-api-key` header when the request host matches
- * [HOST_CURSEFORGE_API] or [HOST_CURSEFORGE_EDGE], provided the API key is not blank.
+ * It automatically injects the `x-api-key` header when the request targets a
+ * CurseForge host, provided the API key is not blank.
  */
 private val CURSEFORGE_INTERCEPTOR = Interceptor { chain ->
     val request = chain.request()
-    val host = request.url.host
-    if (host == HOST_CURSEFORGE_API || host == HOST_CURSEFORGE_EDGE) {
+    if (isCurseForgeHost(request.url.host)) {
         val apiKey = BuildKeys.CURSEFORGE_API
         if (apiKey.isNotBlank()) {
             val newRequest = request.newBuilder()
@@ -130,10 +134,7 @@ val GLOBAL_CLIENT = HttpClient(OkHttp) {
     }
 }.apply {
     requestPipeline.intercept(HttpRequestPipeline.State) {
-        // 检查 host 是否为 CurseForge
-        // 自动添加 CurseForge 的 api 密钥
-        val host = context.url.host
-        if (host == HOST_CURSEFORGE_API || host == HOST_CURSEFORGE_EDGE) {
+        if (isCurseForgeHost(context.url.host)) {
             val apiKey = BuildKeys.CURSEFORGE_API
             if (apiKey.isNotBlank()) {
                 context.header("x-api-key", apiKey)

ZalithLauncher/src/test/java/com/movtery/zalithlauncher/game/download/engine/FileDownloaderE2ETest.kt

@@ -88,9 +88,10 @@ private class FakeSource(
 }
 
 /**
- * 分区守卫源：prefixOnly=true 时仅服务起点位于文件前半段的 Range 请求，
+ * 分区守卫源：prefixOnly=true 时仅服务起点位于文件前半段的请求，
  * 起点越过中位的一律 500；prefixOnly=false 时拒绝起点为 0 的请求，
  * 其余区间正常服务。两者配合可强制一次下载必然发生跨源断点拼接。
+ * 未携带 Range 的请求按起点 0 处理。
  */
 private class GuardedHalfSource(
     private val content: ByteArray,
@@ -102,9 +103,7 @@ private class GuardedHalfSource(
     override fun dispatch(request: RecordedRequest): MockResponse {
         hits.incrementAndGet()
         val range = request.headers["Range"]
-            ?: return MockResponse.Builder().code(500).build()
-
-        val start = RANGE.find(range)!!.groupValues[1].toLong().toInt()
+        val start = range?.let { RANGE.find(it)!!.groupValues[1].toLong().toInt() } ?: 0
         val servesPrefixHalf = start < content.size / 2
 
         if (prefixOnly != servesPrefixHalf) {
@@ -127,6 +126,19 @@ private class GuardedHalfSource(
     }
 }
 
+/** 模拟拒绝任何 Range 请求的 CDN 鉴权层：携带 Range 一律 404，普通 GET 正常服务 */
+private class RangeRejectingSource(private val content: ByteArray) : Dispatcher() {
+    override fun dispatch(request: RecordedRequest): MockResponse {
+        if (request.headers["Range"] != null) {
+            return MockResponse.Builder().code(404).build()
+        }
+        return MockResponse.Builder()
+            .addHeader("Content-Length", content.size.toString())
+            .body(Buffer().write(content))
+            .build()
+    }
+}
+
 class FileDownloaderE2ETest {
 
     private lateinit var workDir: File
@@ -224,6 +236,26 @@ class FileDownloaderE2ETest {
         assertArrayEquals(payload, target.readBytes())
     }
 
+    /** 起点为零的段不得携带 Range：部分 CDN 会直接拒绝任何带 Range 的请求 */
+    @Test
+    fun `fresh download must not carry a range header`() = runBlocking {
+        val source = RangeRejectingSource(payload)
+        val server = startServer(source)
+        val (request, target) = engineRequest("no-range.bin", server.url("/file.bin").toString(), sha1 = sha1HexOf(payload))
+
+        withTimeout(TEST_TIMEOUT_MS) {
+            FileDownloader(
+                request = request,
+                connections = Semaphore(8),
+                stats = DownloadStats(),
+                allowExtraConnection = { false },
+                client = OkHttpClient()
+            ).download()
+        }
+
+        assertArrayEquals(payload, target.readBytes())
+    }
+
     @Test
     fun `unknown size streams till eof`() = runBlocking {
         val server = startServer(FakeSource(payload))