Function checkDenyRuleForGuessedPath

src/tools/PowerShellTool/pathValidation.ts:984–1008

* Best-effort deny check for paths obscured by :: or backtick syntax. * ONLY checks deny rules — never auto-allows. If the stripped guess * doesn't match a deny rule, we fall through to ask as before.

(
  strippedPath: string,
  cwd: string,
  toolPermissionContext: ToolPermissionContext,
  operationType: FileOperationType,
)

 * doesn't match a deny rule, we fall through to ask as before.
 */
function checkDenyRuleForGuessedPath(
  strippedPath: string,
  cwd: string,
  toolPermissionContext: ToolPermissionContext,
  operationType: FileOperationType,
): { resolvedPath: string; rule: PermissionRule } | null {
  // Red-team P7: null bytes make expandPath throw. Pre-existing but
  // defend here since we're introducing a new call path.
  if (!strippedPath || strippedPath.includes('\0')) return null
  // Red-team P3: `~/.ssh/x strips to ~/.ssh/x but expandTilde only fires
  // on leading ~ — the backtick was in front of it. Re-run here.
  const tildeExpanded = expandTilde(strippedPath)
  const abs = isAbsolute(tildeExpanded)
    ? tildeExpanded
    : resolve(cwd, tildeExpanded)
  const { resolvedPath } = safeResolvePath(getFsImplementation(), abs)
  const permissionType = operationType === 'read' ? 'read' : 'edit'
  const denyRule = matchingRuleForInput(
    resolvedPath,
    toolPermissionContext,
    permissionType,
    'deny',
  )
  return denyRule ? { resolvedPath, rule: denyRule } : null
}

/**
 * Validates a file system path, handling tilde expansion.