fix mod update showing when already up to date

update check was comparing file names to decide if an update exists,
but mods from a modpack keep whatever name was in modrinth.index.json
which can differ from modrinth's current file name for the same exact
version. compare version ids from the api instead, name doesn't matter

Author: MaxJubayerYT

app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/modloaders/InstalledModAdapter.java

@@ -218,6 +218,19 @@ private void checkUpdateForEntry(ModEntry entry) throws Exception {
                 ? fileVersion.get("project_id").getAsString() : null;
         if (projectId == null) return;
 
+        // The version this exact jar belongs to, per Modrinth. This is the
+        // canonical identity we compare against below — NOT the file name.
+        // Mods installed from a modpack are saved under whatever file name the
+        // pack's modrinth.index.json recorded, which can legitimately differ
+        // from Modrinth's current "primary file" name for that same version
+        // (the content/hash is identical, only the on-disk name differs). A
+        // name-only comparison flags those as having an update every time,
+        // and clicking "update" just re-downloads the identical version under
+        // Modrinth's canonical name — after which the name matches and the
+        // false positive disappears, i.e. it only happens once per mod.
+        String currentVersionId = fileVersion.has("id")
+                ? fileVersion.get("id").getAsString() : null;
+
         // 3. Get all versions of the project filtered by our mc version + loader
         java.util.HashMap<String, Object> params = new java.util.HashMap<>();
         if (!mFilterMcVersion.isEmpty()) params.put("game_versions", "[\"" + mFilterMcVersion + "\"]");
@@ -229,6 +242,11 @@ private void checkUpdateForEntry(ModEntry entry) throws Exception {
         // Modrinth returns newest first — index 0 is the latest
         JsonObject latest = versions.get(0).getAsJsonObject();
 
+        // If the installed file is already the latest version, there's
+        // nothing to do — regardless of what its file name happens to be.
+        String latestVersionId = latest.has("id") ? latest.get("id").getAsString() : null;
+        if (currentVersionId != null && currentVersionId.equals(latestVersionId)) return;
+
         // 4. Get the latest version's primary file name
         JsonArray files = latest.getAsJsonArray("files");
         if (files == null || files.size() == 0) return;
@@ -248,14 +266,11 @@ private void checkUpdateForEntry(ModEntry entry) throws Exception {
         String latestFileName = latestUrl.substring(latestUrl.lastIndexOf('/') + 1);
         if (latestFileName.contains("?")) latestFileName = latestFileName.substring(0, latestFileName.indexOf('?'));
 
-        // 5. Compare — if the file name differs, an update is available
-        String currentName = entry.file.getName();
-        if (currentName.endsWith(".disabled")) currentName = currentName.replace(".disabled", "");
-
-        if (!currentName.equalsIgnoreCase(latestFileName)) {
-            entry.updateUrl      = latestUrl;
-            entry.updateFileName = latestFileName;
-        }
+        // 5. Reaching here means the early-return above didn't fire, i.e. the
+        // installed file's version id is missing or genuinely differs from
+        // the latest version id — a real update, independent of file naming.
+        entry.updateUrl      = latestUrl;
+        entry.updateFileName = latestFileName;
     }
 
     /** Downloads the update, replaces the existing jar, refreshes the entry. */