From 11a5cb8948e311eaa39946321064f33a041c3a60 Mon Sep 17 00:00:00 2001
From: Ran Benita <ran@unusedvar.com>
Date: Sat, 4 Nov 2023 18:50:57 +0200
Subject: [PATCH 1/2] No-op refactor to make next commit clearer

---
 src/black/lines.py | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/black/lines.py b/src/black/lines.py
index a73c429e3d9..b9716a97cba 100644
--- a/src/black/lines.py
+++ b/src/black/lines.py
@@ -351,9 +351,9 @@ def has_magic_trailing_comma(
 
         if closing.type == token.RSQB:
             if (
-                closing.parent
+                closing.parent is not None
                 and closing.parent.type == syms.trailer
-                and closing.opening_bracket
+                and closing.opening_bracket is not None
                 and is_one_sequence_between(
                     closing.opening_bracket,
                     closing,
@@ -369,16 +369,20 @@ def has_magic_trailing_comma(
             comma = self.leaves[-1]
             if comma.parent is None:
                 return False
-            return (
-                comma.parent.type != syms.subscriptlist
-                or closing.opening_bracket is None
-                or not is_one_sequence_between(
+
+            if (
+                comma.parent.type == syms.subscriptlist
+                and closing.opening_bracket is not None
+                and is_one_sequence_between(
                     closing.opening_bracket,
                     closing,
                     self.leaves,
                     brackets=(token.LSQB, token.RSQB),
                 )
-            )
+            ):
+                return False
+
+            return True
 
         if self.is_import:
             return True

From ac21ded9498aeb54523bdb1ed45562224409ae8c Mon Sep 17 00:00:00 2001
From: Ran Benita <ran@unusedvar.com>
Date: Sat, 4 Nov 2023 19:55:23 +0200
Subject: [PATCH 2/2] Remove redundant condition from `has_magic_comma`

The second `if` cannot be true at its execution point, because it is
already covered by the first `if`. The condition
`comma.parent.type == syms.subscriptlist` always holds if
`closing.parent.type == syms.trailer` holds, because `subscriptlist`
only appears inside `trailer` in the grammar:

```
trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
subscriptlist: (subscript|star_expr) (',' (subscript|star_expr))* [',']
```
---
 src/black/lines.py | 19 -------------------
 1 file changed, 19 deletions(-)

diff --git a/src/black/lines.py b/src/black/lines.py
index b9716a97cba..fb542deae43 100644
--- a/src/black/lines.py
+++ b/src/black/lines.py
@@ -363,25 +363,6 @@ def has_magic_trailing_comma(
             ):
                 return False
 
-            if not ensure_removable:
-                return True
-
-            comma = self.leaves[-1]
-            if comma.parent is None:
-                return False
-
-            if (
-                comma.parent.type == syms.subscriptlist
-                and closing.opening_bracket is not None
-                and is_one_sequence_between(
-                    closing.opening_bracket,
-                    closing,
-                    self.leaves,
-                    brackets=(token.LSQB, token.RSQB),
-                )
-            ):
-                return False
-
             return True
 
         if self.is_import: