Issue #6850: Fix bug in Decimal._parse_format_specifier for formats
with no type specifier.
diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index 0be901a..f7f023d 100644
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -760,6 +760,9 @@
             (',%', '123.456789', '12,345.6789%'),
             (',e', '123456', '1.23456e+5'),
             (',E', '123456', '1.23456E+5'),
+
+            # issue 6850
+            ('a=-7.0', '0.12345', 'aaaa0.1'),
             ]
         for fmt, d, result in test_values:
             self.assertEqual(format(Decimal(d), fmt), result)