Program: 34105
Project: 34105
Buggy source:
/** 
 * Determines a safe teleport spot on player's island or the team island they belong to.
 * @param p PlayerInfo for active player
 * @return Location of a safe teleport spot
 */
protected Location getSafeHomeLocation(final UUID p){
  Location l=players.getHomeLocation(p);
  if (l != null) {
    if (isSafeLocation(l)) {
      return l;
    }
  }
  if (players.inTeam(p)) {
    l=players.getTeamIslandLocation(p);
    if (isSafeLocation(l)) {
      return l;
    }
 else {
      Location tlh=players.getHomeLocation(players.getTeamLeader(p));
      if (tlh != null) {
        if (isSafeLocation(tlh)) {
          return tlh;
        }
      }
    }
  }
 else {
    l=players.getIslandLocation(p);
    if (isSafeLocation(l)) {
      return l;
    }
  }
  if (l == null) {
    getLogger().warning(players.getName(p) + "String_Node_Str");
    return null;
  }
  getLogger().info("String_Node_Str");
  getLogger().info("String_Node_Str");
  Location dl=new Location(l.getWorld(),l.getX() + 0.5D,l.getY() + 5D,l.getZ() + 2.5D,0F,30F);
  if (isSafeLocation(dl)) {
    players.setHomeLocation(p,dl);
    return dl;
  }
  getLogger().info("String_Node_Str");
  dl=new Location(l.getWorld(),l.getX() + 0.5D,l.getY() + 5D,l.getZ() + 0.5D,0F,30F);
  if (isSafeLocation(dl)) {
    players.setHomeLocation(p,dl);
    return dl;
  }
  getLogger().info("String_Node_Str");
  for (int y=l.getBlockY() + 25; y > 0; y--) {
    final Location n=new Location(l.getWorld(),l.getX() + 0.5D,y,l.getZ() + 0.5D);
    if (isSafeLocation(n)) {
      return n;
    }
  }
  getLogger().info("String_Node_Str");
  for (int y=l.getBlockY(); y < 255; y++) {
    final Location n=new Location(l.getWorld(),l.getX() + 0.5D,y,l.getZ() + 0.5D);
    if (isSafeLocation(n)) {
      return n;
    }
  }
  getLogger().info("String_Node_Str");
  for (int y=Settings.island_level; y < l.getWorld().getMaxHeight(); y++) {
    for (int x=l.getBlockX(); x < l.getBlockX() + Settings.island_protectionRange / 2; x++) {
      for (int z=l.getBlockZ(); z < l.getBlockZ() + Settings.island_protectionRange / 2; z++) {
        Location ultimate=new Location(l.getWorld(),(double)x + 0.5D,y,(double)z + 0.5D);
        if (!ultimate.getBlock().equals(Material.AIR)) {
          if (isSafeLocation(ultimate)) {
            players.setHomeLocation(p,ultimate);
            return ultimate;
          }
        }
      }
    }
  }
  for (int y=Settings.island_level; y < l.getWorld().getMaxHeight(); y++) {
    for (int x=l.getBlockX(); x > l.getBlockX() - Settings.island_protectionRange / 2; x--) {
      for (int z=l.getBlockZ(); z < l.getBlockZ() - Settings.island_protectionRange / 2; z--) {
        Location ultimate=new Location(l.getWorld(),(double)x + 0.5D,y,(double)z + 0.5D);
        if (!ultimate.getBlock().equals(Material.AIR)) {
          if (isSafeLocation(ultimate)) {
            players.setHomeLocation(p,ultimate);
            return ultimate;
          }
        }
      }
    }
  }
  for (int y=Settings.island_level - 1; y > 0; y--) {
    for (int x=l.getBlockX(); x < l.getBlockX() + Settings.island_protectionRange / 2; x++) {
      for (int z=l.getBlockZ(); z < l.getBlockZ() + Settings.island_protectionRange / 2; z++) {
        Location ultimate=new Location(l.getWorld(),(double)x + 0.5D,y,(double)z + 0.5D);
        if (!ultimate.getBlock().equals(Material.AIR)) {
          if (isSafeLocation(ultimate)) {
            players.setHomeLocation(p,ultimate);
            return ultimate;
          }
        }
      }
    }
  }
  for (int y=Settings.island_level - 1; y > 0; y--) {
    for (int x=l.getBlockX(); x > l.getBlockX() - Settings.island_protectionRange / 2; x--) {
      for (int z=l.getBlockZ(); z > l.getBlockZ() - Settings.island_protectionRange / 2; z--) {
        Location ultimate=new Location(l.getWorld(),(double)x + 0.5D,y,(double)z + 0.5D);
        if (!ultimate.getBlock().equals(Material.AIR)) {
          if (isSafeLocation(ultimate)) {
            players.setHomeLocation(p,ultimate);
            return ultimate;
          }
        }
      }
    }
  }
  return null;
}

Fixed version (ground truth):
/** 
 * Determines a safe teleport spot on player's island or the team island they belong to.
 * @param p PlayerInfo for active player
 * @return Location of a safe teleport spot
 */
protected Location getSafeHomeLocation(final UUID p){
  Location l=players.getHomeLocation(p);
  if (l != null) {
    if (isSafeLocation(l)) {
      return l;
    }
  }
  Location lPlusOne=l.clone();
  lPlusOne.add(new Vector(0,1,0));
  if (lPlusOne != null) {
    if (isSafeLocation(lPlusOne)) {
      l=lPlusOne;
      return lPlusOne;
    }
  }
  if (players.inTeam(p)) {
    l=players.getTeamIslandLocation(p);
    if (isSafeLocation(l)) {
      return l;
    }
 else {
      Location tlh=players.getHomeLocation(players.getTeamLeader(p));
      if (tlh != null) {
        if (isSafeLocation(tlh)) {
          return tlh;
        }
      }
    }
  }
 else {
    l=players.getIslandLocation(p);
    if (isSafeLocation(l)) {
      return l;
    }
  }
  if (l == null) {
    getLogger().warning(players.getName(p) + "String_Node_Str");
    return null;
  }
  Location dl=new Location(l.getWorld(),l.getX() + 0.5D,l.getY() + 5D,l.getZ() + 2.5D,0F,30F);
  if (isSafeLocation(dl)) {
    players.setHomeLocation(p,dl);
    return dl;
  }
  dl=new Location(l.getWorld(),l.getX() + 0.5D,l.getY() + 5D,l.getZ() + 0.5D,0F,30F);
  if (isSafeLocation(dl)) {
    players.setHomeLocation(p,dl);
    return dl;
  }
  for (int y=l.getBlockY() + 25; y > 0; y--) {
    final Location n=new Location(l.getWorld(),l.getX() + 0.5D,y,l.getZ() + 0.5D);
    if (isSafeLocation(n)) {
      return n;
    }
  }
  for (int y=l.getBlockY(); y < 255; y++) {
    final Location n=new Location(l.getWorld(),l.getX() + 0.5D,y,l.getZ() + 0.5D);
    if (isSafeLocation(n)) {
      return n;
    }
  }
  for (int y=Settings.island_level; y < l.getWorld().getMaxHeight(); y++) {
    for (int x=l.getBlockX(); x < l.getBlockX() + Settings.island_protectionRange / 2; x++) {
      for (int z=l.getBlockZ(); z < l.getBlockZ() + Settings.island_protectionRange / 2; z++) {
        Location ultimate=new Location(l.getWorld(),(double)x + 0.5D,y,(double)z + 0.5D);
        if (!ultimate.getBlock().equals(Material.AIR)) {
          if (isSafeLocation(ultimate)) {
            players.setHomeLocation(p,ultimate);
            return ultimate;
          }
        }
      }
    }
  }
  for (int y=Settings.island_level; y < l.getWorld().getMaxHeight(); y++) {
    for (int x=l.getBlockX(); x > l.getBlockX() - Settings.island_protectionRange / 2; x--) {
      for (int z=l.getBlockZ(); z < l.getBlockZ() - Settings.island_protectionRange / 2; z--) {
        Location ultimate=new Location(l.getWorld(),(double)x + 0.5D,y,(double)z + 0.5D);
        if (!ultimate.getBlock().equals(Material.AIR)) {
          if (isSafeLocation(ultimate)) {
            players.setHomeLocation(p,ultimate);
            return ultimate;
          }
        }
      }
    }
  }
  for (int y=Settings.island_level - 1; y > 0; y--) {
    for (int x=l.getBlockX(); x < l.getBlockX() + Settings.island_protectionRange / 2; x++) {
      for (int z=l.getBlockZ(); z < l.getBlockZ() + Settings.island_protectionRange / 2; z++) {
        Location ultimate=new Location(l.getWorld(),(double)x + 0.5D,y,(double)z + 0.5D);
        if (!ultimate.getBlock().equals(Material.AIR)) {
          if (isSafeLocation(ultimate)) {
            players.setHomeLocation(p,ultimate);
            return ultimate;
          }
        }
      }
    }
  }
  for (int y=Settings.island_level - 1; y > 0; y--) {
    for (int x=l.getBlockX(); x > l.getBlockX() - Settings.island_protectionRange / 2; x--) {
      for (int z=l.getBlockZ(); z > l.getBlockZ() - Settings.island_protectionRange / 2; z--) {
        Location ultimate=new Location(l.getWorld(),(double)x + 0.5D,y,(double)z + 0.5D);
        if (!ultimate.getBlock().equals(Material.AIR)) {
          if (isSafeLocation(ultimate)) {
            players.setHomeLocation(p,ultimate);
            return ultimate;
          }
        }
      }
    }
  }
  return null;
}