Android 4.4 sdcard access new rules: about saving a file that started an activity

问题

I read that with Android 4.4 there are new rules for saving files on sdcard by apps. I have a specific case to ask about:

• an app (activity) A starts another app (activity) B feeding it with a file:// url, say it's a txt file (B is a text editor);
• the app B opens the file and edits it.

Is the called app B able to save the edited content on the same file? Or will the new rules prevent it?

来源：https://stackoverflow.com/questions/24683209/android-4-4-sdcard-access-new-rules-about-saving-a-file-that-started-an-activit