From 31dcb9900d378c0a91ec09715be4fd86fcee7f4a Mon Sep 17 00:00:00 2001
From: ViMaSter <vimaster@noreply.git.hamburg.ccc.de>
Date: Sat, 25 Oct 2025 17:44:59 +0200
Subject: [PATCH] fix: Replace invalid docker tag characters with underscore

---
 .forgejo/workflows/images.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/.forgejo/workflows/images.yml b/.forgejo/workflows/images.yml
index 8c8f5a4..4095e84 100644
--- a/.forgejo/workflows/images.yml
+++ b/.forgejo/workflows/images.yml
@@ -28,7 +28,8 @@ jobs:
           if [ "${{ github.ref_name }}" = "main" ] && [ "${{ github.event_name }}" = "push" ]; then
             echo "tag=latest" >> $GITHUB_OUTPUT
           else
-            echo "tag=${{ github.ref_name }}" >> $GITHUB_OUTPUT
+            # renovate creates sub branches with `/`; these break the tagging in the build process
+            echo "tag=${{ github.ref_name }}" | sed 's/[^a-zA-Z0-9._-]/_/g' >> $GITHUB_OUTPUT
           fi
 
       - name: Build web image