On Sun, Aug 30, 2015 at 8:13 PM, Michael McConville <mmcconv1@sccs.swarthmore.edu> wrote:
free() is specified to be NULL-safe, and I don't know of any implementations that violate this.
I think those NULL checks are meant to avoid double-free bugs. If you assign NULL to a pointer after you free it and check all pointers before free, you avoid trying to free it again. Like there:
error: - if (x509) { - X509_free(x509); - x509 = NULL; - }
But you did find some places they forgot to assign NULL after free. Here's a fun exercise: use Coccinelle to find and patch those. http://coccinelle.lip6.fr/ A semantic patch might look like this: @@ identifier f =~ "free"; expression x; @@ f(x); + x = NULL; Happy hacking! Mansour