diff -r c4c97cabfc16 -r 05654ea5137c hgext/rebase.py
--- a/hgext/rebase.py	Fri Mar 13 19:29:02 2020 -0700
+++ b/hgext/rebase.py	Fri Mar 13 16:39:32 2020 -0700
@@ -815,8 +815,8 @@
         (
             b's',
             b'source',
-            b'',
-            _(b'rebase the specified changeset and descendants'),
+            [],
+            _(b'rebase the specified changesets and their descendants'),
             _(b'REV'),
         ),
         (
@@ -871,7 +871,7 @@
     + cmdutil.dryrunopts
     + cmdutil.formatteropts
     + cmdutil.confirmopts,
-    _(b'[-s REV | -b REV | [-r REV]...] [-d REV] [OPTION]...'),
+    _(b'[[-s REV]... | -b REV | [-r REV]...] [-d REV] [OPTION]...'),
     helpcategory=command.CATEGORY_CHANGE_MANAGEMENT,
 )
 def rebase(ui, repo, **opts):
@@ -1186,7 +1186,7 @@
                 repo,
                 inmemory,
                 opts.get(b'dest', None),
-                opts.get(b'source', None),
+                opts.get(b'source', []),
                 opts.get(b'base', None),
                 opts.get(b'rev', []),
                 destspace=destspace,
@@ -1243,11 +1243,12 @@
             ui.status(_(b'empty "rev" revision set - nothing to rebase\n'))
             return None
     elif srcf:
-        src = scmutil.revrange(repo, [srcf])
+        src = scmutil.revrange(repo, srcf)
         if not src:
             ui.status(_(b'empty "source" revision set - nothing to rebase\n'))
             return None
-        rebaseset = repo.revs(b'(%ld)::', src) or src
+        # `+  (%ld)` to work around `wdir()::` being empty
+        rebaseset = repo.revs(b'(%ld):: + (%ld)', src, src)
     else:
         base = scmutil.revrange(repo, [basef or b'.'])
         if not base: