tests: add test showing current parse of empty string symbol in revset
We support e.g. parents(""), but I think that's by accident and I'll
change it soon.
Differential Revision: https://phab.mercurial-scm.org/D3017
--- a/tests/test-revset2.t Mon Apr 02 08:46:07 2018 -0700
+++ b/tests/test-revset2.t Mon Apr 02 09:06:24 2018 -0700
@@ -575,6 +575,14 @@
hg: parse error: not a symbol
[255]
+test empty string
+
+ $ log ''
+ hg: parse error: empty query
+ [255]
+ $ log 'parents("")'
+ 8
+
we can use patterns when searching for tags
$ log 'tag("1..*")'