Fix possible KeyError using standard handler and "extra" dict (#271)

CHANGELOG.rst

@@ -1,3 +1,9 @@
+`Unreleased`_
+=============
+
+- Modify the way the ``extra`` dict is used by ``LogRecord`` in order to prevent possible ``KeyError`` with standard ``logging`` handlers (`#271 <https://github.com/Delgan/loguru/issues/271>`_).
+
+
 `0.5.0`_ (2020-05-17)
 =====================
 

loguru/_simple_sinks.py

@@ -53,7 +53,7 @@ def write(self, message):
             (),
             (exc.type, exc.value, exc.traceback) if exc else None,
             record["function"],
-            record["extra"],
+            {"extra": record["extra"]},
         )
         if exc:
             record.exc_text = "\n"

tests/test_standard_handler.py

@@ -40,12 +40,21 @@ def test_null_handler(capsys):
 
 def test_extra_dict(capsys):
     handler = StreamHandler(sys.stdout)
-    formatter = Formatter("[%(abc)s] %(message)s")
+    formatter = Formatter("%(extra)s %(message)s")
     handler.setFormatter(formatter)
     logger.add(handler, format="<{extra[abc]}> {message}", catch=False)
     logger.bind(abc=123).info("Extra!")
     out, err = capsys.readouterr()
-    assert out == "[123] <123> Extra!\n"
+    assert out == "{'abc': 123} <123> Extra!\n"
+    assert err == ""
+
+
+def test_no_conflict_with_extra_dict(capsys):
+    handler = StreamHandler(sys.stdout)
+    logger.add(handler, format="{message}", catch=False)
+    logger.bind(args=True, name="foobar", message="Wut?").info("OK!")
+    out, err = capsys.readouterr()
+    assert out == "OK!\n"
     assert err == ""