From a1201a5a8b95d4bddb1d700ca76ac009fb3a7c21 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Tue, 5 Sep 2023 23:13:12 -0700
Subject: [PATCH 1/3] gh-108843: fix ast.unparse for f-string with many quotes

---
 Lib/ast.py               | 20 +++++++++++++++++++-
 Lib/test/test_unparse.py | 10 ++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/Lib/ast.py b/Lib/ast.py
index 17ec7ff6f8bc12..ee2a2db040dbe9 100644
--- a/Lib/ast.py
+++ b/Lib/ast.py
@@ -1236,17 +1236,35 @@ def visit_JoinedStr(self, node):
 
         new_fstring_parts = []
         quote_types = list(_ALL_QUOTES)
+        fallback_to_repr = False
         for value, is_constant in fstring_parts:
             if is_constant:
-                value, quote_types = self._str_literal_helper(
+                value, new_quote_types = self._str_literal_helper(
                     value,
                     quote_types=quote_types,
                     escape_special_whitespace=True,
                 )
+                if set(new_quote_types).isdisjoint(quote_types):
+                    fallback_to_repr = True
+                    break
+                quote_types = new_quote_types
             elif "\n" in value:
                 quote_types = [q for q in quote_types if q in _MULTI_QUOTES]
             new_fstring_parts.append(value)
 
+        if fallback_to_repr:
+            # If we weren't able to find a quote type that works for all parts
+            # of the JoinedStr, fallback to using repr and triple single quotes.
+            quote_types = ["'''"]
+            new_fstring_parts.clear()
+            for value, is_constant in fstring_parts:
+                if is_constant:
+                    value = repr('"' + value)  # force repr to use single quotes
+                    expected_prefix = "'\""
+                    assert value.startswith(expected_prefix), repr(value)
+                    value = value[len(expected_prefix):-1]
+                new_fstring_parts.append(value)
+
         value = "".join(new_fstring_parts)
         quote_type = quote_types[0]
         self.write(f"{quote_type}{value}{quote_type}")
diff --git a/Lib/test/test_unparse.py b/Lib/test/test_unparse.py
index 38c59e6d430b58..c09865894dc280 100644
--- a/Lib/test/test_unparse.py
+++ b/Lib/test/test_unparse.py
@@ -635,6 +635,16 @@ def test_star_expr_assign_target_multiple(self):
         self.check_src_roundtrip("[a, b] = [c, d] = [e, f] = g")
         self.check_src_roundtrip("a, b = [c, d] = e, f = g")
 
+    def test_multiquote_joined_string(self):
+        self.check_ast_roundtrip("f\"'''{1}\\\"\\\"\\\"\" ")
+        self.check_ast_roundtrip("""f"'''{1}""\\"" """)
+        self.check_ast_roundtrip("""f'""\"{1}''' """)
+        self.check_ast_roundtrip("""f'""\"{1}""\\"' """)
+
+        self.check_ast_roundtrip("""f"'''{"\\n"}""\\"" """)
+        self.check_ast_roundtrip("""f'""\"{"\\n"}''' """)
+        self.check_ast_roundtrip("""f'""\"{"\\n"}""\\"' """)
+
 
 class ManualASTCreationTestCase(unittest.TestCase):
     """Test that AST nodes created without a type_params field unparse correctly."""

From 75ab6461fddaf95acd125caad7b1dfd8239d55ab Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Wed, 6 Sep 2023 06:17:26 +0000
Subject: [PATCH 2/3] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20blu?=
 =?UTF-8?q?rb=5Fit.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../next/Library/2023-09-06-06-17-23.gh-issue-108843.WJMhsS.rst  | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Library/2023-09-06-06-17-23.gh-issue-108843.WJMhsS.rst

diff --git a/Misc/NEWS.d/next/Library/2023-09-06-06-17-23.gh-issue-108843.WJMhsS.rst b/Misc/NEWS.d/next/Library/2023-09-06-06-17-23.gh-issue-108843.WJMhsS.rst
new file mode 100644
index 00000000000000..0f15761c14bb7d
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2023-09-06-06-17-23.gh-issue-108843.WJMhsS.rst
@@ -0,0 +1 @@
+Fix an issue in :func:`ast.unparse` when unparsing f-strings containing many quote types.

From 7fb718abe3ef54902e8a46841650a839f0772f07 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Wed, 6 Sep 2023 11:54:44 -0700
Subject: [PATCH 3/3] feedback

---
 Lib/ast.py               | 1 +
 Lib/test/test_unparse.py | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/Lib/ast.py b/Lib/ast.py
index ee2a2db040dbe9..1f54309c8450d8 100644
--- a/Lib/ast.py
+++ b/Lib/ast.py
@@ -1250,6 +1250,7 @@ def visit_JoinedStr(self, node):
                 quote_types = new_quote_types
             elif "\n" in value:
                 quote_types = [q for q in quote_types if q in _MULTI_QUOTES]
+                assert quote_types
             new_fstring_parts.append(value)
 
         if fallback_to_repr:
diff --git a/Lib/test/test_unparse.py b/Lib/test/test_unparse.py
index c09865894dc280..bdf7b0588bee67 100644
--- a/Lib/test/test_unparse.py
+++ b/Lib/test/test_unparse.py
@@ -645,6 +645,10 @@ def test_multiquote_joined_string(self):
         self.check_ast_roundtrip("""f'""\"{"\\n"}''' """)
         self.check_ast_roundtrip("""f'""\"{"\\n"}""\\"' """)
 
+        self.check_ast_roundtrip("""f'''""\"''\\'{"\\n"}''' """)
+        self.check_ast_roundtrip("""f'''""\"''\\'{"\\n\\"'"}''' """)
+        self.check_ast_roundtrip("""f'''""\"''\\'{""\"\\n\\"'''""\" '''\\n'''}''' """)
+
 
 class ManualASTCreationTestCase(unittest.TestCase):
     """Test that AST nodes created without a type_params field unparse correctly."""