From 8a909755f472846962d219b1e84d75126c69a275 Mon Sep 17 00:00:00 2001
From: Oliver Schantz <frequency403@gmail.com>
Date: Mon, 24 Aug 2026 18:38:49 +0200
Subject: [PATCH] #37 using zsync for appimage updates

---
 .github/actions/build-appimage/action.yml | 29 +++++++++++++++++++++--
 .github/workflows/build-and-package.yml   |  8 +++++++
 .github/workflows/build.yml               |  1 +
 3 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/.github/actions/build-appimage/action.yml b/.github/actions/build-appimage/action.yml
index 339c2a6..aaaef4f 100644
--- a/.github/actions/build-appimage/action.yml
+++ b/.github/actions/build-appimage/action.yml
@@ -24,11 +24,18 @@ inputs:
     description: 'Release tag of appimagetool to download'
     required: false
     default: 'continuous'
+  update-information:
+    description: 'zsync update information string (empty disables delta-update embedding)'
+    required: false
+    default: 'gh-releases-zsync|frequency403|OpenSSH-GUI|latest|OpenSSH-GUI-x86_64.AppImage.zsync'
 
 outputs:
   appimage-name:
     description: 'Filename of the produced AppImage'
     value: ${{ steps.build.outputs.appimage-name }}
+  appimage-zsync-name:
+    description: 'Filename of the produced .zsync file (empty if update-information was not set)'
+    value: ${{ steps.build.outputs.appimage-zsync-name }}
 
 runs:
   using: composite
@@ -38,7 +45,7 @@ runs:
       run: |
         set -euo pipefail
         sudo apt-get update -qq
-        sudo apt-get install -y --no-install-recommends librsvg2-bin appstream
+        sudo apt-get install -y --no-install-recommends librsvg2-bin appstream zsync
 
     - name: Download appimagetool
       shell: bash
@@ -116,7 +123,15 @@ runs:
 
         # Assemble AppImage (--appimage-extract-and-run bypasses FUSE requirement)
         APPIMAGE_NAME="${ASSET_PREFIX}-x86_64.AppImage"
-        ARCH=x86_64 ./appimagetool --appimage-extract-and-run AppDir "$APPIMAGE_NAME"
+        UPDATE_INFO="${{ inputs.update-information }}"
+
+        if [[ -n "$UPDATE_INFO" ]]; then
+          ARCH=x86_64 ./appimagetool --appimage-extract-and-run \
+            -u "$UPDATE_INFO" \
+            AppDir "$APPIMAGE_NAME"
+        else
+          ARCH=x86_64 ./appimagetool --appimage-extract-and-run AppDir "$APPIMAGE_NAME"
+        fi
 
         if [[ ! -f "$APPIMAGE_NAME" ]]; then
           echo "::error::appimagetool did not produce $APPIMAGE_NAME"
@@ -124,4 +139,14 @@ runs:
         fi
 
         echo "appimage-name=$APPIMAGE_NAME" >> "$GITHUB_OUTPUT"
+
+        ZSYNC_NAME="${APPIMAGE_NAME}.zsync"
+        if [[ -n "$UPDATE_INFO" ]]; then
+          if [[ ! -f "$ZSYNC_NAME" ]]; then
+            echo "::error::update-information was set but $ZSYNC_NAME was not produced (zsyncmake missing on PATH?)"
+            exit 1
+          fi
+          echo "appimage-zsync-name=$ZSYNC_NAME" >> "$GITHUB_OUTPUT"
+        fi
+
         echo "::notice::AppImage built successfully: $APPIMAGE_NAME"
\ No newline at end of file
diff --git a/.github/workflows/build-and-package.yml b/.github/workflows/build-and-package.yml
index 34bcfd8..65b2f9d 100644
--- a/.github/workflows/build-and-package.yml
+++ b/.github/workflows/build-and-package.yml
@@ -88,6 +88,14 @@ jobs:
           name: ${{ steps.appimage.outputs.appimage-name }}
           path: ${{ steps.appimage.outputs.appimage-name }}
           if-no-files-found: error
+          
+      - name: Upload AppImage zsync file
+        if: matrix.target == 'linux-x64' && steps.appimage.outputs.appimage-zsync-name != ''
+        uses: actions/upload-artifact@v7
+        with:
+          name: ${{ steps.appimage.outputs.appimage-zsync-name }}
+          path: ${{ steps.appimage.outputs.appimage-zsync-name }}
+          if-no-files-found: error
 
       - name: Upload .desktop file
         if: matrix.target == 'linux-x64'
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 327d1c6..7b2d143 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -149,6 +149,7 @@ jobs:
             "OpenSSH-GUI-${VERSION}-Setup.exe" \
             "OpenSSH-GUI-osx-x64" \
             "OpenSSH-GUI-x86_64.AppImage" \
+            "OpenSSH-GUI-x86_64.AppImage.zsync" \
             "appicon.png" \
             "io.github.frequency403.openssh_gui.desktop"
           do