Diff parser: Take care of one line function error recovery

parso/python/diff.py

@@ -726,6 +726,17 @@ class _NodesTree(object):
                 if _func_or_class_has_suite(node):
                     new_nodes.append(node)
                 break
+            try:
+                c = node.children
+            except AttributeError:
+                pass
+            else:
+                # This case basically appears with error recovery of one line
+                # suites like `def foo(): bar.-`. In this case we might not
+                # include a newline in the statement and we need to take care
+                # of that.
+                if c[-1].type in ('error_leaf', 'error_node'):
+                    break
 
             new_nodes.append(node)
 

test/test_diff_parser.py

@@ -1706,3 +1706,25 @@ def test_backslash_with_imports(differ):
     differ.initialize(code1)
     differ.parse(code2, parsers=1)
     differ.parse(code1, parsers=1)
+
+
+def test_one_line_function_error_recovery(differ):
+    code1 = dedent('''\
+        class X:
+            x
+            def y(): word """
+                # a
+                # b
+                c(self)
+        ''')
+    code2 = dedent('''\
+        class X:
+            x
+            def y(): word """
+                # a
+                # b
+                c(\x01+self)
+        ''')
+
+    differ.initialize(code1)
+    differ.parse(code2, parsers=1, copies=1, expect_error_leaves=True)