diff --git a/aider/coders/base_coder.py b/aider/coders/base_coder.py
index 7255e91df..fb9f8c9ac 100755
--- a/aider/coders/base_coder.py
+++ b/aider/coders/base_coder.py
@@ -290,7 +290,7 @@ class Coder:
     def get_abs_fnames_content(self):
         for fname in list(self.abs_fnames):
             content = self.io.read_text(fname)
-            dump(fname, content)
+
             if content is None:
                 relative_fname = self.get_rel_fname(fname)
                 self.io.tool_error(f"Dropping {relative_fname} from the chat.")
@@ -303,8 +303,6 @@ class Coder:
         for _fname, content in self.get_abs_fnames_content():
             all_content += content + "\n"
 
-        all_content = all_content.splitlines()
-
         good = False
         for fence_open, fence_close in self.fences:
             if fence_open in all_content or fence_close in all_content:
diff --git a/tests/test_coder.py b/tests/test_coder.py
index cf5819a1d..5138d59d8 100644
--- a/tests/test_coder.py
+++ b/tests/test_coder.py
@@ -239,5 +239,30 @@ class TestCoder(unittest.TestCase):
         coder.run(with_message="hi")
         self.assertEqual(len(coder.abs_fnames), 1)
 
+    def test_choose_fence(self):
+        # Create a few temporary files
+        _, file1 = tempfile.mkstemp()
+
+        with open(file1, "wb") as f:
+            f.write(b"this contains ``` backticks")
+
+        files = [file1]
+
+        # Initialize the Coder object with the mocked IO and mocked repo
+        coder = Coder.create(
+            models.GPT4, None, io=InputOutput(), openai_api_key="fake_key", fnames=files
+        )
+
+        def mock_send(*args, **kwargs):
+            coder.partial_response_content = "ok"
+            coder.partial_response_function_call = dict()
+
+        coder.send = MagicMock(side_effect=mock_send)
+
+        # Call the run method with a message
+        coder.run(with_message="hi")
+
+        self.assertNotEqual(coder.fence[0], "```")
+
     if __name__ == "__main__":
         unittest.main()