src/http/ngx_http_variables.c:377: error: Integer Overflow L1
  (0 - 1):unsigned64.

src/http/ngx_http_variables.c:376:5: <LHS trace>
374.     v->get_handler = NULL;
375.     v->data = 0;
376.     v->flags = 0;
         ^
377.     v->index = cmcf->variables.nelts - 1;
378. 

src/http/ngx_http_variables.c:376:5: Assignment
374.     v->get_handler = NULL;
375.     v->data = 0;
376.     v->flags = 0;
         ^
377.     v->index = cmcf->variables.nelts - 1;
378. 

src/http/ngx_http_variables.c:377:5: Binary operation: (0 - 1):unsigned64
375.     v->data = 0;
376.     v->flags = 0;
377.     v->index = cmcf->variables.nelts - 1;
         ^
378. 
379.     return cmcf->variables.nelts - 1;
