templater: fix shortest() to evaluate int argument and handle error

mercurial/templater.py

@@ -621,7 +621,9 b' def shortest(context, mapping, args):'
 
     minlength = 4
     if len(args) > 1:
-        minlength = int(args[1][1])
+        minlength = evalinteger(context, mapping, args[1],
+                                # i18n: "shortest" is a keyword
+                                _("shortest() expects an integer minlength"))
 
     cl = mapping['ctx']._repo.changelog
     def isvalid(test):

tests/test-command-template.t

@@ -3219,6 +3219,12 b' Test shortest(node) function:'
   $ hg log --template '{node|shortest}\n' -l1
   e777
 
+  $ hg log -r 0 -T '{shortest(node, "1{"0"}")}\n'
+  f7769ec2ab
+  $ hg log -r 0 -T '{shortest(node, "not an int")}\n'
+  hg: parse error: shortest() expects an integer minlength
+  [255]
+
 Test pad function
 
   $ hg log --template '{pad(rev, 20)} {author|user}\n'