Description
Comparators do not update their output signals when placing a chest to form a double chest, or removing a chest that is part of the double chest. In both cases the chest added or removed does not directly touch the comparator.
Expected behavior
When one of the chests is added/removed that results in the breaking of a chest, it is expected that the redstone signal of a comparator measuring the contents of a chest is being updated as well. In the example given below if either the top-half or the bottom-half is filled with 27 stacks of 64 wool the ouput of the double chest should be 8. Than after breaking the left chest. When placed in the bottom-half the items remain and the output is expected to be 15. If placed the top-half the items drop when breaking the chest, thus the expected ouput is 0.
Steps to reproduce
Place down a chest, than place down another chest to the left of the first chest.
Fill eithe top-half or bottom-half of the chest with 27 stacks of 64 orange wool.
While facing the double chest from the front, place a comparator to the right-side with a redstone dust going out of the comparator.
The redstone dust allows you to measure the signal strength.
Break the part of the chest that does not touch the comparator. (e.g. this should be the left half of the double chest.)
The output signal of the comparator does not change.
This remains the case as long as the contents of the chest are not changed; e.g. you can open/close the chest without the signal changing.
Notes
Orientation does not impact the result.
Severity of the bug is extremely low as contents are often moved around using redstone; as for using it as a signal source, other more viable and often used alternatives exists (e.g. lectern with book, etc.)
Linked issues
Comments

Thank you for your report!
We're actually already tracking this issue in MC-11434, so this ticket is being resolved and linked as a duplicate.
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