From 0fd4d0ab29e99311ab0614f0376639beeae62b14 Mon Sep 17 00:00:00 2001
From: chengyongru <2755839590@qq.com>
Date: Wed, 15 Jul 2026 01:04:27 +0800
Subject: [PATCH] fix(prompts): handle undecodable overrides

---
 nanobot/utils/workspace_prompts.py             |  4 ++--
 tests/agent/test_evaluator.py                  |  8 ++++++++
 tests/command/test_builtin_evaluator_prompt.py | 17 +++++++++++++++++
 3 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/nanobot/utils/workspace_prompts.py b/nanobot/utils/workspace_prompts.py
index 5dfa2a76..104503d8 100644
--- a/nanobot/utils/workspace_prompts.py
+++ b/nanobot/utils/workspace_prompts.py
@@ -25,7 +25,7 @@ def load_workspace_prompt_override(
     Returns the loaded text and its original length. Missing, unreadable, and
     empty files return ``(None, 0)`` so callers can fall back to their default.
     """
-    with suppress(OSError):
+    with suppress(OSError, UnicodeDecodeError):
         text = path.read_text(encoding="utf-8").rstrip()
         if text:
             original_chars = len(text)
@@ -50,7 +50,7 @@ def initialize_workspace_prompt(path: Path, default_prompt: str) -> bool:
             not path.is_file() or bool(path.read_text(encoding="utf-8").strip())
         ):
             return False
-    except OSError:
+    except (OSError, UnicodeDecodeError):
         return False
 
     path.parent.mkdir(parents=True, exist_ok=True)
diff --git a/tests/agent/test_evaluator.py b/tests/agent/test_evaluator.py
index eb19af98..f5f2dff7 100644
--- a/tests/agent/test_evaluator.py
+++ b/tests/agent/test_evaluator.py
@@ -56,6 +56,14 @@ def test_resolve_evaluator_prompt_uses_default_for_empty_override(tmp_path) -> N
     assert resolve_evaluator_prompt(tmp_path) == default_evaluator_prompt()
 
 
+def test_resolve_evaluator_prompt_uses_default_for_undecodable_override(tmp_path) -> None:
+    path = evaluator_prompt_file(tmp_path)
+    path.parent.mkdir()
+    path.write_bytes("Custom evaluator prompt.".encode("utf-16"))
+
+    assert resolve_evaluator_prompt(tmp_path) == default_evaluator_prompt()
+
+
 def test_resolve_evaluator_prompt_caps_workspace_override(tmp_path) -> None:
     path = evaluator_prompt_file(tmp_path)
     path.parent.mkdir()
diff --git a/tests/command/test_builtin_evaluator_prompt.py b/tests/command/test_builtin_evaluator_prompt.py
index 76f91da3..01ebd176 100644
--- a/tests/command/test_builtin_evaluator_prompt.py
+++ b/tests/command/test_builtin_evaluator_prompt.py
@@ -59,6 +59,23 @@ async def test_evaluator_prompt_init_does_not_overwrite_existing_prompt(tmp_path
     assert prompt_file.read_text(encoding="utf-8") == "custom"
 
 
+@pytest.mark.asyncio
+async def test_evaluator_prompt_handles_undecodable_existing_prompt(tmp_path) -> None:
+    prompt_file = tmp_path / "prompts" / "evaluator.md"
+    prompt_file.parent.mkdir()
+    original = "custom".encode("utf-16")
+    prompt_file.write_bytes(original)
+
+    status = await cmd_evaluator_prompt(_make_ctx(tmp_path))
+    init = await cmd_evaluator_prompt(
+        _make_ctx(tmp_path, "/evaluator-prompt init", "init")
+    )
+
+    assert "Heartbeat evaluator prompt: nanobot default" in status.content
+    assert "already exists" in init.content
+    assert prompt_file.read_bytes() == original
+
+
 @pytest.mark.asyncio
 async def test_evaluator_prompt_init_recreates_empty_prompt(tmp_path) -> None:
     prompt_file = tmp_path / "prompts" / "evaluator.md"