tree 1c90161969c9c4910e414d6663491f9ebb34d25b
parent ef58d273d3ee07366593a6dff680a1dddfe0afaa
author George Mount <mount@google.com> 1484246228 -0800
committer George Mount <mount@google.com> 1484246228 -0800

Throw an exception before creating bad child fragment manager.

Bug 34183840

When accessing a fragment's child fragment manager prior to
its being attached, it will forever be in a bad state. This
CL throws an exception when that happens to warn the developer
not to do that.

The original bug came from a restored fragment listed in "active"
having its child fragment manager being accessed. The restored
fragment may not have been attached if it is only in the back
stack.

Test: gradlew connectedCheck in fragments/
Change-Id: I2304ab56bc72ae675c0cde0fc83dac6221ae615e