From cca5cc63de451d5fe34f20beb2c5ee2f26e52b09 Mon Sep 17 00:00:00 2001
From: alexytomi <60690056+alexytomi@users.noreply.github.com>
Date: Fri, 26 Dec 2025 21:03:25 +0800
Subject: [PATCH] fix: Fix mimetype issues with stock android not matching
 .mrpack

We want to be able to grey out files that are not .zip or .mrpack  so
people can have an easier chance of seeing their modpacks. To do this,
we match the `application/x-modrinth-modpack+zip` and `application/zip`
mimetypes as prescribed in the Modrinth documentation
https://support.modrinth.com/en/articles/8802351-modrinth-modpack-format-mrpack.

Stock android does not have `application/x-modrinth-modpack+zip`. OEM
vendors seem to include this in their ROMs, possibly from just using
https://gitlab.freedesktop.org/xdg/shared-mime-info as part of where
they source their additional mimetypes from.

There's a tendency for Android 12 and below to not have the
`application/x-modrinth-modpack+zip` mimetype, likely due to the
addition of it being relatively recent, so we have to account for that
by also adding `application/octet-stream`.

We cannot only have `application/octet-stream` or else it fails to match
.mrpack in systems that have `application/x-modrinth-modpack+zip`.

Sadly there seems to be no reliable way to check whether or the the ROM
has the `application/x-modrinth-modpack+zip` mimetype so we just match
it along with `application/octet-stream` to cover our bases.
---
 .../contracts/OpenDocumentWithExtension.java  | 22 +++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/contracts/OpenDocumentWithExtension.java b/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/contracts/OpenDocumentWithExtension.java
index d761ebba0..8bd5e4547 100644
--- a/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/contracts/OpenDocumentWithExtension.java
+++ b/app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/contracts/OpenDocumentWithExtension.java
@@ -36,10 +36,24 @@ public class OpenDocumentWithExtension extends ActivityResultContract<Object, Ur
         int count = 0;
         for (String extension: extensions) {
             String extensionMimetype = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
-            // This somehow works despite finding no code showing where modrinth was defined.
-            // Guessing that just DocumentsUI supports this, if someone files a bug report saying
-            // they can't select mrpacks with DocumentsUI, remove this and just don't filter at all.
-            if (Objects.equals(extension, "mrpack")) extensionMimetype = "application/x-modrinth-modpack+zip";
+            if (Objects.equals(extension, "mrpack")) {
+                // Special handling here because depending on whether the ROM has
+                // `x-modrinth-modpack+zip` in their mimetypes or not because if it does,
+                // `octet-stream` will no longer match mrpack files.
+
+                // Checking this with MimeTypeMap.hasExtension() and .hasMimeType() always returns
+                // false so we do both instead.
+
+                // `octet-stream` highlights a lot of unrelated files but it's the best
+                // we can do. Mimetypes are built into the ROM after all.
+                // See https://android.googlesource.com/platform/external/mime-support/+/refs/heads/main
+                // or https://android.googlesource.com/platform/frameworks/base/+/refs/heads/main/mime/java-res/android.mime.types
+                extensionsMimeType.add("application/octet-stream");
+                extensionsMimeType.add("application/x-modrinth-modpack+zip");
+                count++;
+                continue;
+            }
+
             if(extensionMimetype == null) continue; // If null is passed, it matches all files
             extensionsMimeType.add(extensionMimetype);
             count++;