Steps to Reproduce:

1. Execute a command such as

   /give @p cake 1 1 {AttributeModifiers:[{AttributeName:"generic.maxHealth"}]}

2. Observe that the command may declare "An unknown error occurred while attempting to perform this command", but you are still given the item.
3. Hover over the item, or attempt to scroll the hotbar over it, and observe that the game immediately crashes.
4. Try re-loading the world. If the bugged item is still in your held slot, you will immediately crash again: the world is now unplayable unless you use a third-party tool to repair it.

What I expected to happen was:
If the command realized that there was an error, why did it still give me a corrupt item? I would have expected to not be given anything, if the tag is incorrectly formatted.

To be honest, this happened on accident; I certainly didn't expect my save to be corrupted.

Note: This is NOT a duplicate of any bug with a similar crash report, unless that bug follows steps similar to the above. I'm aware that similar crashes exist because the crash occurs when attempting to look at a corrupt item. However, this bug report is that /give is able to create corrupt items, not that corrupt items cause crashes.