created an attachment (id=162640)
screenshot

description:
fail to load toc tree when preview attach report document

build:
2.6.0.v20100322-0630

steps to reproduce:
1. run attached report document
2. check the result

actual result:
error happened. see screenshot

expect result:
no error
created an attachment (id=162645)
report
tocreader can't be closed before a toc tree is closed.
in render task, cache a tocreader instance, this tocreader will be closed until the render task is closed. fixed.



verified.