Target NBT is changed despite being reported as unchanged

The bug

When an NBT path modifies the target tag and the NBT operation fails, it is reported as not being changed even though the target tag is actually changed.

How to reproduce

1. Set the dummy value to make the storage mc-208974: non-empty.

   /data modify storage mc-208974: dummy set value 0

MatchObjectNode → AllElementsNode

1. Make sure that _ does not exist.

   /data remove storage mc-208974: _

2. /data modify storage mc-208974: _{}[] set value 0

   → "Nothing changed. The specified properties already have these values"

3. /data get storage mc-208974: _

   → "Storage mc-208974: has the following contents: {}": _ is actually changed to {}.

This case will be automatically resolved when MC-170124 is fixed.

MatchElementNode → AllElementsNode

1. Make sure that _ does not exist.

   /data remove storage mc-208974: _

2. /data modify storage mc-208974: _[{}][] set value 0

   → "Nothing changed. The specified properties already have these values"

3. /data get storage mc-208974: _

   → "Storage mc-208974: has the following contents: [{}]": _ is actually changed to [{}].

This case will be automatically resolved when MC-170124 is fixed.

IndexedElementNode

1. Make sure that _ does not exist.

   /data remove storage mc-208974: _

2. /data modify storage mc-208974: _[0] set value 0

   → "Nothing changed. The specified properties already have these values"

3. /data get storage mc-208974: _

   → "Storage mc-208974: has the following contents: []": _ is actually changed to [].

This case will not be automatically resolved even if MC-170124 is fixed. If _ has a collection tag with size 1 or larger, this command will succeed.