Feature: Path containment startswith bypass prevention (issue #7478 / PR #7801)
  AS a security engineer
  I WANT path containment checks to use semantic comparison instead of string prefix matching
  SO THAT sibling-directory prefix-collision attacks cannot bypass sandbox isolation

  Background:
    Given a temporary sandbox directory "/tmp/sandbox"

  # ---- PathMapper _is_under prefix collision prevention (#7478) ----

  @tdd_issue @tdd_issue_7478
  Scenario: PathMapper rejects sibling-prefix path traversal via relpath containment
    Given I have a PathMapper with host_root "/tmp/sandbox" and container_root "/workspace"
    And a sibling directory with a name that is a prefix of the sandbox root
    When I check whether host path is safe from prefix collision
    Then the prefix collision check should return ``False``

  @tdd_issue @tdd_issue_7478
  Scenario: PathMapper correctly identifies legitimate child paths
    Given I have a PathMapper with host_root "/tmp/sandbox" and container_root "/workspace"
    When I check whether "/tmp/sandbox/src/main.py" is a host path
    Then the host containment result should be true

  @tdd_issue @tdd_issue_7478
  Scenario: PathMapper correctly identifies root equality
    Given I have a PathMapper with host_root "/tmp/sandbox" and container_root "/workspace"
    When I check whether "/tmp/sandbox" is a host path
    Then the host containment result should be true

  @tdd_issue @tdd_issue_7478
  Scenario: PathMapper rejects sibling-prefix escape path
    Given I have a PathMapper with host_root "/tmp/sandbox" and container_root "/workspace"
    And a file "escape-evil.txt" with content "malicious" at "/tmp/sandbox-escape/escape-evil.txt"
    When I check whether "/tmp/sandbox-escape/escape-evil.txt" is a host path
    Then the host containment result should be false

  @tdd_issue @tdd_issue_7478
  Scenario: PathMapper maps root path exactly (no relative component)
    Given I have a PathMapper with host_root "/tmp/sandbox" and container_root "/workspace"
    When I map the host path "/tmp/sandbox" to container
    Then the mapped path should be "/workspace"

  @tdd_issue @tdd_issue_7478
  Scenario: PathMapper maps a child path correctly through relpath
    Given I have a PathMapper with host_root "/tmp/sandbox" and container_root "/workspace"
    When I map the host path "/tmp/sandbox/src/main.py" to container
    Then the mapped path should be "/workspace/src/main.py"