revset: ensure we are reversing a list (issue3530)

mercurial/revset.py

@@ -1151,6 +1151,8 b' def reverse(repo, subset, x):'
     Reverse order of set.
     """
     l = getset(repo, subset, x)
+    if not isinstance(l, list):
+        l = list(l)
     l.reverse()
     return l
 

tests/test-revset.t

@@ -372,6 +372,17 b' quoting needed'
   4
   3
   2
+  $ log 'reverse(all())'
+  9
+  8
+  7
+  6
+  5
+  4
+  3
+  2
+  1
+  0
   $ log 'rev(5)'
   5
   $ log 'sort(limit(reverse(all()), 3))'