From 40c5083c759c9e3420932aa082add905bb6950b1 Mon Sep 17 00:00:00 2001
From: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Date: Fri, 26 Apr 2024 20:03:21 -0700
Subject: [PATCH] Fix another f-string regression

---
 CHANGES.md                     | 2 ++
 src/blib2to3/pgen2/tokenize.py | 2 +-
 tests/data/cases/pep_701.py    | 6 ++++++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/CHANGES.md b/CHANGES.md
index f56f40f250e..71da1ff96c1 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -25,6 +25,8 @@
 ### Parser
 
 <!-- Changes to the parser or to version autodetection -->
+- Fix regression where Black failed to parse a multiline f-string containing
+  another multiline f-string (#4339)
 
 ### Performance
 
diff --git a/src/blib2to3/pgen2/tokenize.py b/src/blib2to3/pgen2/tokenize.py
index f66087bd0e3..bac59b75f17 100644
--- a/src/blib2to3/pgen2/tokenize.py
+++ b/src/blib2to3/pgen2/tokenize.py
@@ -623,7 +623,7 @@ def generate_tokens(
                 epos = (lnum, end)
                 tokenline = contline + line
                 if (
-                    fstring_state.current() == STATE_NOT_FSTRING
+                    fstring_state.current() in (STATE_NOT_FSTRING, STATE_IN_BRACES)
                     and not is_fstring_start(token)
                 ):
                     yield (STRING, token, spos, epos, tokenline)
diff --git a/tests/data/cases/pep_701.py b/tests/data/cases/pep_701.py
index 9e157bd6fd1..d72d91c6799 100644
--- a/tests/data/cases/pep_701.py
+++ b/tests/data/cases/pep_701.py
@@ -125,6 +125,9 @@
 
 f'{{\\"kind\\":\\"ConfigMap\\",\\"metadata\\":{{\\"annotations\\":{{}},\\"name\\":\\"cluster-info\\",\\"namespace\\":\\"amazon-cloudwatch\\"}}}}'
 
+f"""{'''
+'''}"""
+
 # output
 
 x = f"foo"
@@ -252,3 +255,6 @@
 f"{1:{2}d}"
 
 f'{{\\"kind\\":\\"ConfigMap\\",\\"metadata\\":{{\\"annotations\\":{{}},\\"name\\":\\"cluster-info\\",\\"namespace\\":\\"amazon-cloudwatch\\"}}}}'
+
+f"""{'''
+'''}"""