# HG changeset patch
# User Gregory Szorc <gregory.szorc@gmail.com>
# Date 1467839662 25200
# Node ID 3f854e3bcdd109fe86c5bda911b76408184a2d98
# Parent  c16e2087660f939c02ede8805b23faa366d1eb7d
client: raise KeyError from __getitem__ (BC)

object.__getitem__ is supposed to raise either IndexError or KeyError
(depending on whether the thing is a sequence or a mapping). Before,
we would raise ValueError because that's what the context constructor
raises.

I choose to raise KeyError because IndexError felt a bit too limiting.
This does sacrifice some magic with for loops handling IndexError.
However, iteration of this object should be handled by a custom
__iter__, so I don't think this is a problem.

diff -r c16e2087660f -r 3f854e3bcdd1 hglib/client.py
--- a/hglib/client.py	Wed Jul 06 14:11:02 2016 -0700
+++ b/hglib/client.py	Wed Jul 06 14:14:22 2016 -0700
@@ -1631,7 +1631,10 @@
         return self._version
 
     def __getitem__(self, changeid):
-        return context.changectx(self, changeid)
+        try:
+            return context.changectx(self, changeid)
+        except ValueError as e:
+            raise KeyError(*e.args)
 
     def __contains__(self, changeid):
         """
diff -r c16e2087660f -r 3f854e3bcdd1 tests/test-context.py
--- a/tests/test-context.py	Wed Jul 06 14:11:02 2016 -0700
+++ b/tests/test-context.py	Wed Jul 06 14:14:22 2016 -0700
@@ -17,6 +17,8 @@
         self.append('c', 'c')
         rev1, node1 = self.client.commit(b('second'), addremove=True)
 
+        self.assertRaises(KeyError, self.client.__getitem__, 'doesnotexist')
+
         ctx = self.client[node0]
 
         self.assertEquals(ctx.description(), b('first'))