If suckless.org is about code quality, memset to zero or calloc are certainly not a good idea. Code that sucks less is code that compiles for many years to come, and strives for maximum portability, within reason. Setting a NULL pointer to all-zero-bit is IMHO a sign of bad coding. Whether Anselm wants that to go in the code or not is his preroative, hence why I maintain my own patch queue with a patch code cleancode, that does what I think is better.
And yes, a static char *p will be initialised to 0, and be == 0, because a 0 (zero) symbol in a source code file is th representation of both the constant 0 and the NULL pointer. NULL (as a cast from 0 to (void *)0 )is only really necessary for lazy programmers using variadic functions (such as printf).
