patchbomb: Fail early if no revs given to email

hgext/patchbomb.py

@@ -226,7 +226,9 b' def patchbomb(ui, repo, *revs, **opts):'
     if not opts['test']:
         mail.validateconfig(ui)
 
-    # option handling
+    if not (revs or opts.get('rev') or opts.get('outgoing')):
+        raise util.Abort(_('specify at least one changeset with -r or -o'))
+
     commands.setremoteconfig(ui, opts)
     if opts.get('outgoing') and opts.get('bundle'):
         raise util.Abort(_("--outgoing mode always on with --bundle; do not re-specify --outgoing"))