From ab9276e4450745b4c125c863dc2c53d74908fd73 Mon Sep 17 00:00:00 2001
From: emme1t <149944796+emme1t@users.noreply.github.com>
Date: Sat, 19 Sep 2026 02:25:17 -0700
Subject: [PATCH] Fix full-rewrite code fences with CRLF and literal languages

---
 openevolve/utils/code_utils.py |  2 +-
 tests/test_code_utils.py       | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/openevolve/utils/code_utils.py b/openevolve/utils/code_utils.py
index cde6a971af..dc97b0cb7e 100644
--- a/openevolve/utils/code_utils.py
+++ b/openevolve/utils/code_utils.py
@@ -103,7 +103,7 @@ def parse_full_rewrite(llm_response: str, language: str = "python") -> Optional[
     Returns:
         Extracted code or None if not found
     """
-    code_block_pattern = r"```" + language + r"\n(.*?)```"
+    code_block_pattern = r"```" + re.escape(language) + r"\r?\n(.*?)```"
     matches = re.findall(code_block_pattern, llm_response, re.DOTALL)
 
     if matches:
diff --git a/tests/test_code_utils.py b/tests/test_code_utils.py
index 20f269b7a9..e9187ad245 100644
--- a/tests/test_code_utils.py
+++ b/tests/test_code_utils.py
@@ -9,12 +9,33 @@
     apply_diff,
     extract_diffs,
     format_diff_summary,
+    parse_full_rewrite,
 )
 
 
 class TestCodeUtils(unittest.TestCase):
     """Tests for code utilities"""
 
+    def test_parse_full_rewrite_line_endings(self):
+        for newline in ("\n", "\r\n"):
+            with self.subTest(newline=repr(newline)):
+                code = f"def solve():{newline}    return 42"
+                response = f"Updated program:{newline}```python{newline}{code}{newline}```"
+                result = parse_full_rewrite(response)
+                self.assertEqual(result, code)
+                namespace = {}
+                exec(result, namespace)
+                self.assertEqual(namespace["solve"](), 42)
+
+    def test_parse_full_rewrite_literal_language(self):
+        response = "```c\nint wrong;\n```\n```c++\nint correct;\n```"
+        self.assertEqual(parse_full_rewrite(response, "c++"), "int correct;")
+
+    def test_parse_full_rewrite_fallbacks(self):
+        for response in ("```\nx = 1\n```", "x = 1"):
+            with self.subTest(response=response):
+                self.assertEqual(parse_full_rewrite(response), "x = 1")
+
     def test_extract_diffs(self):
         """Test extracting diffs from a response"""
         diff_text = """