>>>>> Looking at the code in sssvlv.c, it uses tavl_find3() to search the values, but the >>>>> code in tavl_find3() looks to me that it only works properly with an exact match >>>>> type of matching rule: >>>>> >>>>> Avlnode * >>>>> tavl_find3( Avlnode *root, const void *data, AVL_CMP fcmp, int *ret ) >>>>> { >>>>> int cmp = -1, dir; >>>>> Avlnode *prev = root; >>>>> >>>>> while ( root != 0&& (cmp = (*fcmp)( data, root->avl_data )) != 0 ) { >>>>> prev = root; >>>>> dir = cmp> 0; >>>>> root = avl_child( root, dir ); >>>>> } >>>>> *ret = cmp; >>>>> return root ? root : prev; >>>>> } >>>>> >>>>> since the while loop terminates when the fcmp function returns 0 (i.e. exact match). >>>>> >>>> >>>> I think I've worked out where the problem is. >>>> Firstly, there's a comment before tavl_find3() saying >>>> /* >>>> * tavl_find2 - returns Avlnode instead of data pointer. >>>> * tavl_find3 - as above, but returns Avlnode even if no match is found. >>>> * also set *ret = last comparison result, or -1 if root == NULL. >>>> */ >>>> >>>> but the "or -1 if root == NULL" is not done. > > Not true; since cmp is initialized to -1, it will return -1 when the function > is entered with root == NULL. There is no bug in this part.It depends how you read the comment.