cgroupv2: add test for reexec

.github/workflows/tunasync.yml

@@ -71,6 +71,20 @@ jobs:
       run: |
         make build-test-worker
         sudo cgexec -g "*:/" bash -c "echo 0 > /sys/fs/cgroup/systemd/tasks; exec sudo -u $USER env USECURCGROUP=1 TERM=xterm-256color cgexec -g cpu,memory:tunasync ./worker.test -test.v=true -test.coverprofile profile2.cov -test.run TestCgroup"
+        touch /tmp/dummy_exec
+        chmod +x /tmp/dummy_exec
+        run_test_reexec (){
+          case="$1"
+          shift
+          argv0="$1"
+          shift
+          (TESTREEXEC="$case" TERM=xterm-256color exec -a "$argv0" ./worker.test -test.v=true -test.coverprofile "profile5_$case.cov" -test.run TestReexec -- "$@")
+        }
+        run_test_reexec 1 tunasync-exec __dummy__
+        run_test_reexec 2 tunasync-exec /tmp/dummy_exec
+        run_test_reexec 3 tunasync-exec /tmp/dummy_exec 3< <(echo -n "abrt")
+        run_test_reexec 4 tunasync-exec /tmp/dummy_exec 3< <(echo -n "cont")
+        run_test_reexec 5 tunasync-exec2
 
     - name: Set up Docker Buildx
       uses: docker/setup-buildx-action@v1
@@ -209,7 +223,8 @@ jobs:
         CUSER="$(id --user --name)"
         "${HOME}/go/bin/gocovmerge" profile.cov profile2.cov \
           "umlrootfs/home/${CUSER}/profile3.cov" \
-          "umlrootfs/home/${CUSER}/profile4.cov" > profile-all.cov
+          "umlrootfs/home/${CUSER}/profile4.cov" \
+          profile5_*.cov > profile-all.cov
 
     - name: Convert coverage to lcov
       uses: jandelgado/gcov2lcov-action@v1.0.0