rfc: free and errno

[Walter Harms <wharms@bfs.de>]

Hi List

free() is generaly assumed not to modify errno. 

Lately there was a bugfix posting on the busybox mailing list, because:

"musl libc's mallocing free() may modify errno if kernel does not support
MADV_FREE which causes echo to echo with error when it shouldn't."

In future  it seems that POSIX with require free() not to change errno.

after much soul searching i have still no idea if that should be documented in
the free(3) man page. Any comments ?

re,
 wh