From aefdd35d9bd63c71b8d1d004baf770ecf5198ed7 Mon Sep 17 00:00:00 2001
From: Alexandre Teixeira <111787685+alteixeira20@users.noreply.github.com>
Date: Fri, 2 Oct 2026 23:23:40 +0100
Subject: [PATCH] fix(runtime): preserve resource denial diagnostics

---
 src/tool_execution.py           |  4 +--
 tests/test_wave3_diagnostics.py | 48 +++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 2 deletions(-)
 create mode 100644 tests/test_wave3_diagnostics.py

diff --git a/src/tool_execution.py b/src/tool_execution.py
index f54eb9d47..4aa8c6be2 100644
--- a/src/tool_execution.py
+++ b/src/tool_execution.py
@@ -1425,7 +1425,7 @@ async def execute_tool_block(
                 owner=owner, session_id=session_id, workspace=workspace,
                 tool_name=getattr(block, "tool_type", None), content=getattr(block, "content", None)))
         admitted = valid and (authority.permits(operation) or exact_admission)
-    except (ValueError, TypeError, AttributeError) as error:
+    except (ValueError, TypeError) as error:
         return f"{getattr(block, 'tool_type', '')}: invalid arguments", {
             "error": (f"Tool arguments are not valid JSON: {error}"
                       if isinstance(error, json.JSONDecodeError) else str(error)),
@@ -1503,7 +1503,7 @@ async def execute_tool_block(
                 authority, operation, document_id=active_document_id,
                 approved=pending.owned_operation if pending is not None else None,
                 exact_admission=exact_admission)
-    except (ValueError, TypeError, OSError, RuntimeError, AttributeError) as error:
+    except (ValueError, TypeError, OSError) as error:
         return f"{transport}: BLOCKED", {
             "error": str(error), "exit_code": 1, "blocked": True,
             "failure_kind": "resource_identity_denied",
diff --git a/tests/test_wave3_diagnostics.py b/tests/test_wave3_diagnostics.py
new file mode 100644
index 000000000..358a6a43e
--- /dev/null
+++ b/tests/test_wave3_diagnostics.py
@@ -0,0 +1,48 @@
+"""Unexpected programming defects must not look like successful policy denial."""
+import pytest
+from src import tool_execution
+from src.agent_runtime.authority import ExactOperation, OperationGrant, RequestAuthority
+from src.agent_runtime.resources import ResourceIdentityError
+from src.tool_capabilities import ToolRunSecurityContext
+from src.tool_types import ToolBlock
+
+
+@pytest.mark.parametrize('seam,tool,content', [
+    ('bind_backend_for_operation', 'bash', 'printf probe'),
+    ('resolve_process_operation', 'bash', 'printf probe'),
+    ('admit_owned_operation', 'edit_document', '{"document_id":"doc","content":"changed"}'),
+])
+@pytest.mark.parametrize('error_type', [AttributeError, ResourceIdentityError, ValueError, TypeError])
+async def test_binding_errors_keep_diagnostic_identity(tmp_path, monkeypatch, seam, tool, content, error_type):
+    authority = RequestAuthority('request', 'alice', 'thread', str(tmp_path), (OperationGrant(tool),))
+    monkeypatch.setattr(tool_execution, '_owner_is_admin', lambda owner: True)
+    def broken(*args, **kwargs):
+        raise error_type('injected defect')
+    monkeypatch.setattr(tool_execution, seam, broken)
+    args = dict(owner='alice', session_id='thread', workspace=str(tmp_path), request_authority=authority,
+                security_context=ToolRunSecurityContext())
+    if error_type is AttributeError:
+        with pytest.raises(AttributeError, match='injected defect'):
+            await tool_execution.execute_tool_block(ToolBlock(tool, content), **args)
+    else:
+        _, result = await tool_execution.execute_tool_block(ToolBlock(tool, content), **args)
+        assert result['failure_kind'] == 'resource_identity_denied' and result['blocked']
+
+
+async def test_argument_normalization_defect_propagates(tmp_path, monkeypatch):
+    authority = RequestAuthority('request', 'alice', 'thread', str(tmp_path), (OperationGrant('bash'),))
+    def broken(*args, **kwargs): raise AttributeError('internal-only diagnostic')
+    monkeypatch.setattr(ExactOperation, 'normalize', broken)
+    with pytest.raises(AttributeError):
+        await tool_execution.execute_tool_block(ToolBlock('bash', 'printf probe'), owner='alice',
+            session_id='thread', workspace=str(tmp_path), request_authority=authority,
+            security_context=ToolRunSecurityContext())
+
+
+@pytest.mark.parametrize('content', ['{invalid', None])
+async def test_expected_bad_input_still_has_authority_denial(tmp_path, content):
+    authority = RequestAuthority('request', 'alice', 'thread', str(tmp_path), (OperationGrant('api_call'),))
+    _, result = await tool_execution.execute_tool_block(ToolBlock('api_call', content), owner='alice',
+        session_id='thread', workspace=str(tmp_path), request_authority=authority,
+        security_context=ToolRunSecurityContext())
+    assert result['failure_kind'] == 'request_authority_denied'