tools: normalize file tool pagination bounds

tests/tools/test_file_operations.py

@@ -19,6 +19,8 @@ from tools.file_operations import (
     BINARY_EXTENSIONS,
     IMAGE_EXTENSIONS,
     MAX_LINE_LENGTH,
+    normalize_read_pagination,
+    normalize_search_pagination,
 )
 
 
@@ -192,6 +194,17 @@ def file_ops(mock_env):
 
 
 class TestShellFileOpsHelpers:
+    def test_normalize_read_pagination_clamps_invalid_values(self):
+        assert normalize_read_pagination(offset=0, limit=0) == (1, 1)
+        assert normalize_read_pagination(offset=-10, limit=-5) == (1, 1)
+        assert normalize_read_pagination(offset="bad", limit="bad") == (1, 500)
+        assert normalize_read_pagination(offset=2, limit=999999) == (2, 2000)
+
+    def test_normalize_search_pagination_clamps_invalid_values(self):
+        assert normalize_search_pagination(offset=-10, limit=-5) == (0, 1)
+        assert normalize_search_pagination(offset="bad", limit="bad") == (0, 50)
+        assert normalize_search_pagination(offset=3, limit=0) == (3, 1)
+
     def test_escape_shell_arg_simple(self, file_ops):
         assert file_ops._escape_shell_arg("hello") == "'hello'"
 

tests/tools/test_file_operations_edge_cases.py

@@ -146,3 +146,61 @@ class TestCheckLintBracePaths:
 
         assert result.success is False
         assert "SyntaxError" in result.output
+
+
+# =========================================================================
+# Pagination bounds
+# =========================================================================
+
+
+class TestPaginationBounds:
+    """Invalid pagination inputs should not leak into shell commands."""
+
+    def test_read_file_clamps_offset_and_limit_before_building_sed_range(self):
+        env = MagicMock()
+        env.cwd = "/tmp"
+        ops = ShellFileOperations(env)
+        commands = []
+
+        def fake_exec(command, *args, **kwargs):
+            commands.append(command)
+            if command.startswith("wc -c"):
+                return MagicMock(exit_code=0, stdout="12")
+            if command.startswith("head -c"):
+                return MagicMock(exit_code=0, stdout="line1\nline2\n")
+            if command.startswith("sed -n"):
+                return MagicMock(exit_code=0, stdout="line1\n")
+            if command.startswith("wc -l"):
+                return MagicMock(exit_code=0, stdout="2")
+            return MagicMock(exit_code=0, stdout="")
+
+        with patch.object(ops, "_exec", side_effect=fake_exec):
+            result = ops.read_file("notes.txt", offset=0, limit=0)
+
+        assert result.error is None
+        assert "     1|line1" in result.content
+        sed_commands = [cmd for cmd in commands if cmd.startswith("sed -n")]
+        assert sed_commands == ["sed -n '1,1p' 'notes.txt'"]
+
+    def test_search_clamps_offset_and_limit_before_building_head_pipeline(self):
+        env = MagicMock()
+        env.cwd = "/tmp"
+        ops = ShellFileOperations(env)
+        commands = []
+
+        def fake_exec(command, *args, **kwargs):
+            commands.append(command)
+            if command.startswith("test -e"):
+                return MagicMock(exit_code=0, stdout="exists")
+            if command.startswith("rg --files"):
+                return MagicMock(exit_code=0, stdout="a.py\n")
+            return MagicMock(exit_code=0, stdout="")
+
+        with patch.object(ops, "_has_command", side_effect=lambda cmd: cmd == "rg"), \
+             patch.object(ops, "_exec", side_effect=fake_exec):
+            result = ops.search("*.py", target="files", path=".", offset=-4, limit=-2)
+
+        assert result.files == ["a.py"]
+        rg_commands = [cmd for cmd in commands if cmd.startswith("rg --files")]
+        assert rg_commands
+        assert "| head -n 1" in rg_commands[0]

tests/tools/test_file_tools.py

@@ -45,6 +45,19 @@ class TestReadFileHandler:
         read_file_tool("/tmp/big.txt", offset=10, limit=20)
         mock_ops.read_file.assert_called_once_with("/tmp/big.txt", 10, 20)
 
+    @patch("tools.file_tools._get_file_ops")
+    def test_invalid_offset_and_limit_are_normalized_before_dispatch(self, mock_get):
+        mock_ops = MagicMock()
+        result_obj = MagicMock()
+        result_obj.content = "line1"
+        result_obj.to_dict.return_value = {"content": "line1", "total_lines": 1}
+        mock_ops.read_file.return_value = result_obj
+        mock_get.return_value = mock_ops
+
+        from tools.file_tools import read_file_tool
+        read_file_tool("/tmp/big.txt", offset=0, limit=0)
+        mock_ops.read_file.assert_called_once_with("/tmp/big.txt", 1, 1)
+
     @patch("tools.file_tools._get_file_ops")
     def test_exception_returns_error_json(self, mock_get):
         mock_get.side_effect = RuntimeError("terminal not available")
@@ -191,6 +204,21 @@ class TestSearchHandler:
             limit=10, offset=5, output_mode="count", context=2,
         )
 
+    @patch("tools.file_tools._get_file_ops")
+    def test_search_normalizes_invalid_pagination_before_dispatch(self, mock_get):
+        mock_ops = MagicMock()
+        result_obj = MagicMock()
+        result_obj.to_dict.return_value = {"files": []}
+        mock_ops.search.return_value = result_obj
+        mock_get.return_value = mock_ops
+
+        from tools.file_tools import search_tool
+        search_tool(pattern="class", target="files", path="/src", limit=-5, offset=-2)
+        mock_ops.search.assert_called_once_with(
+            pattern="class", path="/src", target="files", file_glob=None,
+            limit=1, offset=0, output_mode="content", context=0,
+        )
+
     @patch("tools.file_tools._get_file_ops")
     def test_search_exception_returns_error(self, mock_get):
         mock_get.side_effect = RuntimeError("no terminal")