tests: convert ParseError arguments to str on Python 3

Arguments internally are bytes. Printing the exception on Python 3
will include b'' prefixes. This test file uses a .out file, which
doesn't support conditional output. The easiest way to get this to
pass on Python 3 is to normalize the exception before printing so
there are no b'' prefixes.

Differential Revision: https://phab.mercurial-scm.org/D5793

tests/test-trusted.py

@@ -222,15 +222,25 b" f = open(b'.hg/hgrc', 'wb')"
 f.write(b'foo')
 f.close()
 
+# This is a hack to remove b'' prefixes from ParseError.__bytes__ on
+# Python 3.
+def normalizeparseerror(e):
+    if pycompat.ispy3:
+        args = [a.decode('utf-8') for a in e.args]
+    else:
+        args = e.args
+
+    return error.ParseError(*args)
+
 try:
     testui(user=b'abc', group=b'def', silent=True)
 except error.ParseError as inst:
-    bprint(inst)
+    bprint(normalizeparseerror(inst))
 
 try:
     testui(debug=True, silent=True)
 except error.ParseError as inst:
-    bprint(inst)
+    bprint(normalizeparseerror(inst))
 
 print()
 bprint(b'# access typed information')