.el .ie does not work in groff 1.21

[Jim Avera]

groff <<'EOF'
.warn
.ie     1 .tm action1
.el .ie 0 .tm action2
.el .ie 0 .tm action3
.el       .tm defaultaction
EOF
action1
<standard input>:4: warning: unbalanced .el request
<standard input>:5: warning: unbalanced .el request

---discussion---

These warnings seem wrong.  In

  .ie cond anything

it nowhere says that "anything" may not be another conditional,
so you ought be able to write "case" constructs like the above
without having to enclose all the "else" branches in \{\ ... \}