ERR_set_mark, ERR_pop_to_mark

 #include <openssl/err.h>
 int ERR_set_mark(void);
 int ERR_pop_to_mark(void);

ERR_set_mark() sets a mark on the current topmost error record if there is one.

ERR_pop_to_mark() will pop the top of the error stack until a mark is found. The mark is then removed. If there is no mark, the whole stack is removed.

ERR_set_mark() returns 0 if the error stack is empty, otherwise 1.

ERR_pop_to_mark() returns 0 if there was no mark in the error stack, which implies that the stack became empty, otherwise 1.

err(3)

ERR_set_mark() and ERR_pop_to_mark() were added in OpenSSL 0.9.8.