[U-Boot] [PATCH v2 1/1] malloc: don't compare pointers to 0

[Wolfgang Denk]

Dear Heinrich,

In message <20171110204634.20515-1-xypron.glpk at gmx.de> you wrote:
> 0 is not a pointer. So do not compare pointers to 0.

Who says so?  0 can be the value of a pointer to a valid, existing
address.  For example a large number of Power Architecture systems
map the RAM beginning at physical address 0, so if you want to
wrtite to the very first byte in memory your pointer value is 0.

> Do not return 0 from functions with a pointer return
> type.

Why?  It could be a valid value - or not.

> -				if (new_address == 0)
> +				if (!new_address)

In which way is "new_address == 0" and "!new_address" different?


Best regards,

Wolfgang Denk

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