Ensure that worktree is uploaded on failure, fix insane range-diff invocation

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

.github/workflows/rebase-shears.yml

@@ -69,6 +69,7 @@ jobs:
           git fetch upstream --no-tags
 
       - name: Run rebase (single branch)
+        id: rebase-single
         if: env.BRANCH != 'all'
         shell: bash
         run: |
@@ -89,14 +90,12 @@ jobs:
           GH_TOKEN: ${{ secrets.COPILOT_GITHUB_TOKEN }}
 
       - name: Run rebase (all branches)
+        id: rebase-all
         if: env.BRANCH == 'all'
         shell: bash
         run: |
           for BRANCH in seen next main maint; do
-            echo ""
-            echo "========================================"
-            echo "Processing shears/$BRANCH"
-            echo "========================================"
+            echo "::group::Processing shears/$BRANCH"
             
             case "$BRANCH" in
               main) UPSTREAM="upstream/master" ;;
@@ -107,27 +106,35 @@ jobs:
             
             if test 0 = "$(git rev-list --count "origin/shears/$BRANCH..$UPSTREAM")"; then
               echo "Nothing to do: $UPSTREAM has no new commits"
+              echo "::endgroup::"
               continue
             fi
             
             ./ci/rebase-branch.sh "origin/shears/$BRANCH" "$UPSTREAM" ./ci || {
+              echo "::endgroup::"
               echo "Rebase failed for shears/$BRANCH"
               exit 1
             }
+            echo "::endgroup::"
           done
-          
-          echo ""
-          echo "All branches processed successfully!"
         env:
           GH_TOKEN: ${{ secrets.COPILOT_GITHUB_TOKEN }}
 
+      - name: Create recovery archive on failure
+        if: failure() && (steps.rebase-single.outputs.worktree || steps.rebase-all.outputs.worktree)
+        shell: bash
+        run: |
+          worktree="${{ steps.rebase-single.outputs.worktree || steps.rebase-all.outputs.worktree }}"
+          cd "$worktree"
+          git bundle create recovery.bundle HEAD REBASE_HEAD refs/rewritten/* 2>/dev/null || true
+          tar -czf recovery-archive.tar.gz .
+
       - name: Upload recovery archive on failure
-        if: failure()
+        if: failure() && (steps.rebase-single.outputs.worktree || steps.rebase-all.outputs.worktree)
         uses: actions/upload-artifact@v4
         with:
           name: recovery-archive
-          path: "**/recovery-archive.tar.gz"
-          if-no-files-found: ignore
+          path: "${{ steps.rebase-single.outputs.worktree || steps.rebase-all.outputs.worktree }}/recovery-archive.tar.gz"
 
       - name: Push results
         if: env.PUSH == 'true'

ci/rebase-branch.sh

@@ -394,6 +394,11 @@ WORKTREE_DIR=$(mktemp -d)
 REPORT_FILE="$WORKTREE_DIR/conflict-report.md"
 trap 'git worktree remove --force "$WORKTREE_DIR"' EXIT
 
+# Output worktree path early so recovery steps can find it on failure
+if test -n "$GITHUB_OUTPUT"; then
+	echo "worktree=$WORKTREE_DIR" >>"$GITHUB_OUTPUT"
+fi
+
 # Extract local branch name from origin/shears/foo -> shears/foo
 LOCAL_BRANCH=${SHEARS_BRANCH#origin/}
 
@@ -468,8 +473,9 @@ PARENT_COUNT=$(git rev-list --parents -1 "$MARKER_IN_RESULT" | wc -w)
 test "$PARENT_COUNT" -eq 3 || # commit itself + 2 parents
 	die "Marker should have 2 parents, found $((PARENT_COUNT - 1))"
 
-# Generate range-diff
-RANGE_DIFF=$(git range-diff "$OLD_UPSTREAM..$OLD_MARKER^2" "$NEW_UPSTREAM..$MARKER_IN_RESULT^2" || echo "Unable to generate range-diff")
+# Generate range-diff (always use markers as base, never upstream branches)
+# MARKER_IN_RESULT^2 is the old tip (saved as second parent of new marker)
+RANGE_DIFF=$(git range-diff "$OLD_MARKER..$MARKER_IN_RESULT^2" "$MARKER_IN_RESULT..HEAD" || echo "Unable to generate range-diff")
 
 # Annotate range-diff with upstream OIDs for skipped commits
 if test -s "$SKIPPED_MAP_FILE"; then
@@ -500,9 +506,8 @@ echo "Rebase completed: $(git rev-parse --short HEAD)"
 cat "$REPORT_FILE"
 echo "To push: cd $WORKTREE_DIR && git push --force origin HEAD:${SHEARS_BRANCH##*/}"
 
-# For GitHub Actions: output variables
+# For GitHub Actions: output variables (worktree already output early)
 if test -n "$GITHUB_OUTPUT"; then
-	echo "worktree=$WORKTREE_DIR" >>"$GITHUB_OUTPUT"
 	echo "report=$REPORT_FILE" >>"$GITHUB_OUTPUT"
 	echo "head=$(git rev-parse HEAD)" >>"$GITHUB_OUTPUT"
 fi