INTERNAL ERROR: when doing a line break

[MartinThoma]

To Reproduce

Run black over a foo.py file which contains this:

class Foo:
    def bar(self):
            if "xxxxxxxxxxx" in ["aaaaaaaaaaaaaa", "bbbbbbbbbbbbb", "cccccccccccccccccccccc"] or ("xxxxxxx" is None):
                pass

to get:

$ black foo.py
error: cannot format foo.py: INTERNAL ERROR: Black produced different code on the second pass of the formatter.  Please report a bug on https://github.com/psf/black/issues.  This diff might be helpful: /tmp/blk_s6trbp84.log
Oh no! 💥 💔 💥
1 file failed to reformat.

Environment (please complete the following information):

• Version: black, version 20.8b1
• OS and Python version: Linux/Python 3.8.6

Does this bug also happen on master? Yes

[MartinThoma]

$ cat /tmp/blk_s6trbp84.log
Mode(target_versions=set(), line_length=88, string_normalization=True, experimental_string_processing=False, is_pyi=False)
--- source
+++ first pass
@@ -1,5 +1,8 @@
-
 class Foo:
     def bar(self):
-            if "xxxxxxxxxxx" in ["aaaaaaaaaaaaaa", "bbbbbbbbbbbbb", "cccccccccccccccccccccc"] or ("xxxxxxx" is None):
-                pass
+        if "xxxxxxxxxxx" in [
+            "aaaaaaaaaaaaaa",
+            "bbbbbbbbbbbbb",
+            "cccccccccccccccccccccc",
+        ] or ("xxxxxxx" is None):
+            pass
--- first pass
+++ second pass
@@ -1,8 +1,12 @@
 class Foo:
     def bar(self):
-        if "xxxxxxxxxxx" in [
-            "aaaaaaaaaaaaaa",
-            "bbbbbbbbbbbbb",
-            "cccccccccccccccccccccc",
-        ] or ("xxxxxxx" is None):
+        if (
+            "xxxxxxxxxxx"
+            in [
+                "aaaaaaaaaaaaaa",
+                "bbbbbbbbbbbbb",
+                "cccccccccccccccccccccc",
+            ]
+            or ("xxxxxxx" is None)
+        ):
             pass

[ichard26]

Hello!

All reproduction cases in this issue format without error on master. The fixing commit was 8672af3 from PR GH-2126. I'll be marking this issue as a duplicate of GH-1629 since that's what GH-2126 aimed to fix and it's highly likely this issue falls under GH-1629.

Since we use the issue tracker as a reflection of what's on master, I'll be closing this issue. If you have any issues, especially with the new (but stable) output, please open a new issue. Oh and the fix should be available in a published release soon, see GH-2125 for more info.

Thank you for reporting!