Fix: Incorrect file access when loading context/mode

Context or mode argument referencing a known name (e.g. `--context anitgravity`) could result in
incorrect file access if a corresponding local file existed (e.g. `./antigravity` binary);
file access is now guarded with path detection (file ending or path separator must be present)

Fixes #1558

CHANGELOG.md

@@ -10,6 +10,9 @@ Status of the `main` branch. Changes prior to the next official version change w
     Gemini) launched from inside a worktree to the parent repo, causing stale reads and misdirected edits.
   - Fix: CLI flags on `start-mcp-server` could incorrectly be saved to the global configuration file if the
     list of projects was modified (triggering a save of the configuration with transient overrides applied)
+  - Fix: context or mode argument referencing a known name (e.g. `--context anitgravity`) could result in   
+    incorrect file access if a corresponding local file existed (e.g. `./antigravity` binary);
+    file access is now guarded with path detection (file ending or path separator must be present)
 
 * Language Servers:
   - `typescript_vts`: Add `initialization_options` setting in `ls_specific_settings.typescript_vts`.

src/serena/config/context_mode.py

@@ -26,6 +26,10 @@ if TYPE_CHECKING:
 log = logging.getLogger(__name__)
 
 
+def looks_like_yaml_path(s: str) -> bool:
+    return os.sep in s or (os.altsep and os.altsep in s) or s.lower().endswith((".yml", ".yaml"))
+
+
 @dataclass(kw_only=True)
 class SerenaAgentMode(ToolInclusionDefinition, ToStringMixin):
     """Represents a mode of operation for the agent, typically read off a YAML file.
@@ -124,16 +128,15 @@ class SerenaAgentMode(ToolInclusionDefinition, ToStringMixin):
 
     @classmethod
     def load(cls, name_or_path: str | Path) -> Self:
-        # Check if it's a file path that exists
-        path = Path(name_or_path)
-        if path.exists() and path.is_file():
-            return cls.from_yaml(name_or_path)
-
-        # If it looks like a file path but doesn't exist, raise FileNotFoundError
-        name_or_path_str = str(name_or_path)
-        if os.sep in name_or_path_str or (os.altsep and os.altsep in name_or_path_str) or name_or_path_str.endswith((".yml", ".yaml")):
-            raise FileNotFoundError(f"Mode file not found: {path.resolve()}")
+        # If it is a path or looks like a path, load from file
+        if isinstance(name_or_path, Path) or looks_like_yaml_path(str(name_or_path)):
+            path = Path(name_or_path)
+            if path.exists() and path.is_file():
+                return cls.from_yaml(name_or_path)
+            else:
+                raise FileNotFoundError(f"Mode file not found: {path.resolve()}")
 
+        # load from name
         return cls.from_name(str(name_or_path))
 
     def has_prompt(self) -> bool:
@@ -239,15 +242,13 @@ class SerenaAgentContext(ToolInclusionDefinition, ToStringMixin):
 
     @classmethod
     def load(cls, name_or_path: str | Path) -> Self:
-        # Check if it's a file path that exists
-        path = Path(name_or_path)
-        if path.exists() and path.is_file():
-            return cls.from_yaml(name_or_path)
-
-        # If it looks like a file path but doesn't exist, raise FileNotFoundError
-        name_or_path_str = str(name_or_path)
-        if os.sep in name_or_path_str or (os.altsep and os.altsep in name_or_path_str) or name_or_path_str.endswith((".yml", ".yaml")):
-            raise FileNotFoundError(f"Context file not found: {path.resolve()}")
+        # If it is a path or looks like a path, load from file
+        if isinstance(name_or_path, Path) or looks_like_yaml_path(str(name_or_path)):
+            path = Path(name_or_path)
+            if path.exists() and path.is_file():
+                return cls.from_yaml(name_or_path)
+            else:
+                raise FileNotFoundError(f"Context file not found: {path.resolve()}")
 
         return cls.from_name(str(name_or_path))