revset: fix crash by repo.revs('%d', tip + 1)

IndexError shouldn't be raised from a revset predicate. The error message
is copied from scmutil.revsymbol().

mercurial/revset.py

@@ -2109,7 +2109,10 b' def _rev(repo, subset, x):'
         # i18n: "rev" is a keyword
         raise error.ParseError(_(b"rev expects a number"))
     if l not in _virtualrevs:
-        repo.changelog.node(l)  # check that the rev exists
+        try:
+            repo.changelog.node(l)  # check that the rev exists
+        except IndexError:
+            raise error.RepoLookupError(_(b"unknown revision '%d'") % l)
     return subset & baseset([l])
 
 

tests/test-template-functions.t

@@ -1269,6 +1269,12 b' default. join() should agree with the de'
   2147483647
   $ hg log -T '{revset("%d", rev)}\n' -r'null'
   -1
+  $ hg log -T '{revset("%d", rev + 1)}\n' -r'tip'
+  abort: unknown revision '3'!
+  [255]
+  $ hg log -T '{revset("%d", rev - 1)}\n' -r'null'
+  abort: unknown revision '-2'!
+  [255]
 
 Invalid arguments passed to revset()