From 5302e3a98777c75ed8f4d943d5152e5cc9b2c0d0 Mon Sep 17 00:00:00 2001
From: mfishma <mfishma@users.noreply.github.com>
Date: Tue, 21 Jul 2026 12:32:13 -0700
Subject: [PATCH] Fix deep link installation for mods containing + (plus sign)
 (#6464)

* ffix: preserve literal '+' in deep link URI thru API call

* chore: check for missing projects during installs

* chore: remove accidental test files and quote error ID

* fix rustfmt formatting for the change
---
 apps/app-frontend/src/providers/content-install.ts |  5 +++++
 packages/app-lib/src/state/cache.rs                | 11 +++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/apps/app-frontend/src/providers/content-install.ts b/apps/app-frontend/src/providers/content-install.ts
index e4605b5f5c..7cd4b96b3b 100644
--- a/apps/app-frontend/src/providers/content-install.ts
+++ b/apps/app-frontend/src/providers/content-install.ts
@@ -807,6 +807,11 @@ export function createContentInstall(opts: {
 	) {
 		const project: Labrinth.Projects.v2.Project = await get_project(projectId, 'must_revalidate')
 
+		if (!project) {
+			opts.handleError(`Project not found: '${projectId}'`)
+			return
+		}
+
 		if (project.project_type === 'modpack') {
 			const version = versionId ?? project.versions[project.versions.length - 1]
 			const packs = await list()
diff --git a/packages/app-lib/src/state/cache.rs b/packages/app-lib/src/state/cache.rs
index 99ae6d3457..74a78c794d 100644
--- a/packages/app-lib/src/state/cache.rs
+++ b/packages/app-lib/src/state/cache.rs
@@ -1105,8 +1105,15 @@ impl CachedEntry {
                 .collect::<Vec<_>>()
                 .chunks(MAX_REQUEST_SIZE)
                 .map(|chunk| {
-                    serde_json::to_string(&chunk)
-                        .map(|keys| format!("{api_url}{url}{keys}"))
+                    serde_json::to_string(&chunk).map(|keys| {
+                        format!(
+                            "{api_url}{url}{}",
+                            url::form_urlencoded::byte_serialize(
+                                keys.as_bytes()
+                            )
+                            .collect::<String>()
+                        )
+                    })
                 })
                 .collect::<Result<Vec<_>, _>>()?;