link_inode: handle hash collisions in DIR_ITEM

src/ntfs2btrfs.cpp

@@ -1307,7 +1307,34 @@ static void link_inode(root& r, uint64_t inode, uint64_t dir, const string_view&
 
  hash = calc_crc32c(0xfffffffe, (const uint8_t*)name.data(), (uint32_t)name.length());
 
- add_item(r, dir, TYPE_DIR_ITEM, hash, di, (uint16_t)dilen); // FIXME - handle hash collisions
+ if (r.items.count(KEY{dir, TYPE_DIR_ITEM, hash}) == 0)
+ add_item(r, dir, TYPE_DIR_ITEM, hash, di, (uint16_t)dilen);
+ else { // hash collision
+ auto& ent = r.items.at(KEY{dir, TYPE_DIR_ITEM, hash});
+
+ if (ent.len != 0) {
+ void* data = malloc(ent.len + dilen);
+
+ if (!data)
+ throw bad_alloc();
+
+ memcpy(data, ent.data, ent.len);
+ memcpy((uint8_t*)data + ent.len, di, dilen);
+
+ free(ent.data);
+
+ ent.data = data;
+ ent.len += (uint32_t)dilen;
+ } else {
+ ent.data = malloc(dilen);
+ if (!ent.data)
+ throw bad_alloc();
+
+ ent.len = (uint32_t)dilen;
+ memcpy(ent.data, di, dilen);
+ }
+ }
+
  add_item(r, dir, TYPE_DIR_INDEX, seq, di, (uint16_t)dilen);
  } catch (...) {
  free(di);