[Bug] Inconsistent /bank error messages

Minecraft Username:
314
(Honestly, who else would file such a ridiculously thorough bug report for something minor like this?)

Brief Description:
/bank (deposit|withdraw) commands usually return "Please provide a valid amount." error messages when you provide invalid values. Some values (see the list below) either don't return any message at all (/bank withdraw) or show the "/bank <deposit|withdraw|balance> <amount>" help message (/bank deposit).

Instructions:

Code:

Malformed string input:
    /bank withdraw abcde
    /bank withdraw 1e2e3
    /bank withdraw null
    /bank withdraw infinity (note the lowercase 'i')
    /bank deposit abcde
    /bank deposit 1e2e3
    /bank deposit null
    /bank deposit infinity (Again, lowercase 'i')
Strings that return Infinity:
    /bank withdraw 1e314 (Double.MAX_VALUE is somewhere around 1.8e308, so any higher exponent returns Infinity.)
    /bank withdraw Infinity (note the uppercase 'I')
    /bank deposit 1e314 (See explanation above)
    /bank deposit Infinity (note the uppercase 'I')
Strings that return NaN:
    /bank withdraw NaN
    /bank deposit NaN

(Color coding: Error message, no error message, syntax help¹)

As you can see, whenever the provided parameter returns NaN or Infinity, the deposit command will show the syntax help¹ while the withdraw command will simply do nothing at all.

How many times did you recreate this?:
2 tries per listed command; reproduced 100% of the time.

Result:

• Commands marked in red do not reply with "Please provide a valid amount", there is simply no reply at all.
• Commands marked in blue reply with the syntax help¹.

Expected Result:

• Commands marked in red should reply with "Please provide a valid amount", just like the commands in green already do.
• Commands marked in blue could remain that way because the syntax is invalid, but IMO it would be better to show the "Please provide a valid amount" error message as well (and limit the syntax help to cases where the value parameter is omitted completely).

Evidence:
N/A. Easy to reproduce, but it's difficult to show a screenshot of "nothing happens".

Additional Information:
I blame Double.parseDouble(String) and java.lang.Double's Infinity/NaN edge cases.


Yes, I created a bug report based on the Java API Specification.

---

¹ "syntax help" refers to

Code:

/bank <deposit|withdraw|balance> <amount>

instead of showing an actual

Code:

Please provide a valid amount.

error message.