In the man page for realloc(3p)[1] does correctly mention the differences in the different C standards of the realloc(<somePointer>,0) behaviour. The malloc(3)[2] manpage, which also describes the realloc() function, does not mention it and says memory is freed with realloc(<somePointer>,0). This is the case in glibc but never C standards, C99 or newer, do not specify that memory is freed when size is 0 and there are systems which do not free memory with realloc(<somePointer>,0).

I argue both manpages should mention the different standards and that realloc(<somePointer>,0) is non-portable.


[1] https://man7.org/linux/man-pages/man3/realloc.3p.html
[2] https://man7.org/linux/man-pages/man3/malloc.3.html