gh-138539: Fix wrong indent for docstrings in IDLE

Lib/idlelib/editor.py

@@ -1456,10 +1456,10 @@ def newline_and_indent_event(self, event):
             c = y.get_continuation_type()
             if c != pyparse.C_NONE:
                 # The current statement hasn't ended yet.
-                if c == pyparse.C_STRING_FIRST_LINE:
-                    # After the first line of a string do not indent at all.
-                    pass
-                elif c == pyparse.C_STRING_NEXT_LINES:
+                if (
+                    c == pyparse.C_STRING_FIRST_LINE
+                    or c == pyparse.C_STRING_NEXT_LINES
+                ):
                     # Inside a string which started before this line;
                     # just mimic the current indent.
                     text.insert("insert", indent, self.user_input_insert_tags)

Lib/idlelib/idle_test/test_editor.py

@@ -140,9 +140,9 @@ def test_indent_and_newline_event(self):
                           '  def f1(self, a, b):',
                           '  def f1(self,\n         a, b):\n',
                           '1.15'),
-                 TestInfo('Inside string with one line - no indent.',
+                 TestInfo('Inside string with one line.',
                           '  """Docstring."""',
-                          '  """Docstring.\n"""\n',
+                          '  """Docstring.\n  """\n',
                           '1.15'),
                  TestInfo('Inside string with more than one line.',
                           '  """Docstring.\n  Docstring Line 2"""',

Misc/NEWS.d/next/IDLE/2025-09-06-06-01-45.gh-issue-138539.jBvls0.rst

@@ -0,0 +1 @@
+Fix wrong indent for docstrings