--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-obsolete-bounds-checking.t	Sun Oct 01 12:54:35 2017 +0100
@@ -0,0 +1,23 @@
+Create a repo, set the username to something more than 255 bytes, then run hg amend on it.
+
+  $ unset HGUSER
+  $ cat >> $HGRCPATH << EOF
+  > [ui]
+  > username = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa <very.long.name@example.com>
+  > [extensions]
+  > amend =
+  > [experimental]
+  > stabilization=createmarkers,exchange
+  > EOF
+  $ hg init tmpa
+  $ cd tmpa
+  $ echo a > a
+  $ hg add
+  adding a
+  $ hg commit -m "Initial commit"
+  $ echo a >> a
+  $ hg amend 2>&1 | egrep -v '^(\*\*|  )'
+  transaction abort!
+  rollback completed
+  Traceback (most recent call last):
+  mercurial.error.ProgrammingError: obsstore metadata value cannot be longer than 255 bytes (value "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa <very.long.name@example.com>" for key "user" is 285 bytes)