Fix heapsort, add test

src/heapsort.c

@@ -3,39 +3,43 @@
 
 static void
 uc_sift(unsigned char *base, size_t start, size_t count, size_t width,
-     uc_hs_cmp cmp)
+     uc_hs_cmp cmp, uc_hs_swp swap, void *cookie)
 {
     size_t root = start, child;
 
     while ((root * 2 + 1) < count) {
         child = root * 2 + 1;
-        if (child < (count - 1)
-            && cmp(&base[child * width], &base[(child + 1) * width]) < 0)
-            child++;
+        if (child < (count - 1)) {
+            int rc = cmp(&base[child * width], &base[(child + 1) * width], cookie);
+            if (rc < 0) {
+                child++;
+            }
+        }
 
-        if (cmp(&base[root * width], &base[child * width]) < 0) {
-            memcpy(base + root * width, base + child * width, width);
+        if (cmp(&base[root * width], &base[child * width], cookie) < 0) {
+            swap(base + root * width, base + child * width);
             root = child;
-        } else
+        } else {
             return;
+        }
     }
 }
 
 void
 uc_heapsort(void *base_, size_t count, size_t width,
-     uc_hs_cmp cmp)
+     uc_hs_cmp cmp, uc_hs_swp swap, void *cookie)
 {
     int start = count / 2 - 1, end = count - 1;
     unsigned char *base = base_;
 
     while (start >= 0) {
-        uc_sift(base, start, count, width, cmp);
+        uc_sift(base, start, count, width, cmp, swap, cookie);
         start--;
     }
 
     while (end > 0) {
-        memcpy(base + end * width, base, width);
-        uc_sift(base, 0, end, width, cmp);
+        swap(base + end * width, base);
+        uc_sift(base, 0, end, width, cmp, swap, cookie);
         end--;
     }
 }