ref: 201c4b566f54ee0e5cb5122f9a9bf1a68b3466e2
dir: /sys/src/libndb/ndbdiscard.c/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <ndb.h>
/* remove a from t and free it */
Ndbtuple*
ndbdiscard(Ndbtuple *t, Ndbtuple *a)
{
	Ndbtuple *nt;
	/* unchain a */
	for(nt = t; nt != nil; nt = nt->entry){
		if(nt->line == a)
			nt->line = a->line;
		if(nt->entry == a)
			nt->entry = a->entry;
	}
	/* a may be start of chain */
	if(t == a)
		t = a->entry;
	/* free a */
	a->entry = nil;
	ndbfree(a);
	return t;
}