rebase: abort if the user tries to rebase the working copy

I think it's more correct to treat `hg rebase -r 'wdirrev()' -d foo`
as `hg co -m foo`, but I'm instead making it error out. That's partly
because it's probably what the user wanted (in the case I heard from a
user, they had done `hg rebase -s f` where `f` resolved to `wdir()`)
and partly because I don't want to think about more complicated cases
where the user specifies the working copy together with other commits.

Differential Revision: https://phab.mercurial-scm.org/D8057

hgext/rebase.py

@@ -37,6 +37,7 b' from mercurial import ('
     hg,
     merge as mergemod,
     mergeutil,
+    node as nodemod,
     obsolete,
     obsutil,
     patch,
@@ -1265,8 +1266,7 b' def _definedestmap('
         if not src:
             ui.status(_(b'empty "source" revision set - nothing to rebase\n'))
             return None
-        rebaseset = repo.revs(b'(%ld)::', src)
-        assert rebaseset
+        rebaseset = repo.revs(b'(%ld)::', src) or src
     else:
         base = scmutil.revrange(repo, [basef or b'.'])
         if not base:
@@ -1341,6 +1341,8 b' def _definedestmap('
                 )
             return None
 
+    if nodemod.wdirrev in rebaseset:
+        raise error.Abort(_(b'cannot rebase the working copy'))
     rebasingwcp = repo[b'.'].rev() in rebaseset
     ui.log(
         b"rebase",

tests/test-rebase-parameters.t

@@ -93,11 +93,12 b' These fail:'
   [1]
 
   $ hg rebase --rev 'wdir()' --dest 6
-  abort: working directory revision cannot be specified
+  abort: cannot rebase the working copy
   [255]
 
-  $ hg rebase --source 'wdir()' --dest 6 2>&1 | grep assert
-      assert rebaseset
+  $ hg rebase --source 'wdir()' --dest 6
+  abort: cannot rebase the working copy
+  [255]
 
   $ hg rebase --source '1 & !1' --dest 8
   empty "source" revision set - nothing to rebase