From 8794b7c3ffe3a49b85c388989e645d5b08ce710b Mon Sep 17 00:00:00 2001
From: Rohit Behera <126186063+r0h1tb@users.noreply.github.com>
Date: Sat, 24 Oct 2026 18:47:22 +0530
Subject: [PATCH] fix: drop the fence language tag when a full rewrite falls
 back to any code block

When the response's fence language doesn't match the configured one
(```py, ```python3, ```js for javascript, ...), parse_full_rewrite fell
back to a pattern that captured everything after the backticks, so the tag
became the first line of the extracted program.
---
 openevolve/utils/code_utils.py | 4 ++--
 tests/test_code_utils.py       | 9 +++++++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/openevolve/utils/code_utils.py b/openevolve/utils/code_utils.py
index f4823fe34..5ef3f7cf0 100644
--- a/openevolve/utils/code_utils.py
+++ b/openevolve/utils/code_utils.py
@@ -243,8 +243,8 @@ def parse_full_rewrite(llm_response: str, language: str = "python") -> Optional[
     if matches:
         return matches[0].strip()
 
-    # Fallback to any code block
-    code_block_pattern = r"```(.*?)```"
+    # Fallback to any code block, without its language tag if it has one
+    code_block_pattern = r"```(?:[^\s`]*[ \t]*\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 d0a93a174..d1d08f7a9 100644
--- a/tests/test_code_utils.py
+++ b/tests/test_code_utils.py
@@ -51,6 +51,15 @@ def test_parse_full_rewrite_fallbacks(self):
             with self.subTest(response=response):
                 self.assertEqual(parse_full_rewrite(response), "x = 1")
 
+    def test_parse_full_rewrite_other_language_tag(self):
+        for tag in ("py", "python3", "Python", "c++"):
+            for newline in ("\n", "\r\n"):
+                with self.subTest(tag=tag, newline=repr(newline)):
+                    response = f"```{tag}{newline}x = 1{newline}```"
+                    self.assertEqual(parse_full_rewrite(response), "x = 1")
+        response = "```js\nconsole.log(1)\n```"
+        self.assertEqual(parse_full_rewrite(response, "javascript"), "console.log(1)")
+
     def test_extract_diffs(self):
         """Test extracting diffs from a response"""
         diff_text = """