Lines Matching refs:NULL
31 if (rootp == NULL)
32 return NULL;
34 while (*rootp != NULL) { /* Knuth's T1: */
50 q->llink = q->rlink = NULL;
64 if (rootp == NULL)
65 return NULL;
67 while (*rootp != NULL) { /* T1: */
76 return NULL;
94 if (rootp == NULL || (p = *rootp) == NULL)
95 return NULL;
102 if (*rootp == NULL)
103 return NULL; /* key not found */
106 if ((q = (*rootp)->llink) == NULL) /* Left NULL? */
108 else if (r != NULL) { /* Right link is NULL? */
109 if (r->llink == NULL) { /* D2: Find successor */
112 } else { /* D3: Find NULL link */
113 for (q = r->llink; q->llink != NULL; q = r->llink)