Hi Ikegami, After I fixed it, it passed but then it gives me another error shown below

*** glibc detected *** free(): invalid next size (fast): 0x000000000089aaa0 *** Abort

I don't know what happen, would you please help? The code is posted below. By the way, is that possible you can scan thru my code to see if I am doing what I supposed to do?

MODULE = nDB      PACKAGE = geom

REQUIRE: 1.925

SV*
get_bbox(rects)
   SV* rects
    INIT:
   rect* result;
   rect** arrRects;
   I32 nRects = 0;
   SV* sv;
   SV* rv = newRV_noinc(sv);
   if (rv == NULL)
      warn("RV has not been created sucessfully!\n");
   SV** ssv;
   double minx,miny,maxx,maxy,tmp_minx,tmp_miny,tmp_maxx,tmp_maxy;
   int n;

   if ((!SvROK(rects))||(SvTYPE(SvRV(rects)) != SVt_PVAV)||((nRects = 
+av_len((AV*)SvRV(rects))) < 0)) {
      XSRETURN_UNDEF;
   }

   arrRects = (rect**)safemalloc(sizeof(rect*)*(nRects));
   for (n=0;n<=nRects;n++) {
      ssv = av_fetch((AV*)SvRV(rects), n, 0);
      if (ssv != NULL) {
         arrRects[n] = (rect*)malloc(sizeof(rect));
         if (arrRects[n] == NULL) {
            warn("get_bbox: unable to malloc rect\n");
         } else {
            arrRects[n] = (rect*)SvIV((SV*)SvRV(*ssv));
         }
      }
   }
    CODE:
   minx = (*arrRects)->x1();
   miny = (*arrRects)->y1();
   maxx = (*arrRects)->x2();
   maxy = (*arrRects)->y2();

   for (n=1;n<=nRects;n++) {
      tmp_minx = (*(arrRects+n))->x1();
      tmp_miny = (*(arrRects+n))->y1();
      tmp_maxx = (*(arrRects+n))->x2();
      tmp_maxy = (*(arrRects+n))->y2();

      if (tmp_minx < minx)
         minx = tmp_minx;
      if (tmp_miny < miny)
         miny = tmp_miny;
      if (tmp_maxx > maxx)
         maxx = tmp_maxx;
      if (tmp_maxy > maxy)
         maxy = tmp_maxy;
   }

   result = (rect*)malloc(sizeof(rect*));
   rect r(minx,miny,maxx,maxy);
   *result = r;
   sv_setref_iv(rv,"rect",(IV) result);
   RETVAL = rv;

    OUTPUT:
   RETVAL
[download]

Oh I found it. The line

result = (rect*)safemalloc(sizeof(rect*));

should be

result = (rect*)safemalloc(sizeof(rect));

Regards,

Thanks Ikegami, I really appreciate your advice. I will fix this and see if it passed.