diff -r 59638c6fcb70 -r 1c04894e8fe1 mercurial/revsetlang.py
--- a/mercurial/revsetlang.py	Sun Jan 27 13:18:53 2019 +0900
+++ b/mercurial/revsetlang.py	Sun Jan 27 13:28:45 2019 +0900
@@ -246,6 +246,9 @@
     If any of the sides omitted, and if no default provided, ParseError will
     be raised.
     """
+    if x and (x[0] == 'string' or x[0] == 'symbol'):
+        n = getinteger(x, err1)
+        return n, n
     a, b = getrange(x, err1)
     return getinteger(a, err2, deffirst), getinteger(b, err2, deflast)