[Demonstration 1]

[Buggy Method]
@Override
public void register(String key, String value) {
    try {
        int endOfNumber = key.indexOf('^');
        if (endOfNumber == -1) {
            endOfNumber = key.indexOf('.');
        }
        if (endOfNumber == -1) {
            endOfNumber = key.length();
        }
        String number = key.substring(0, endOfNumber);
        int id = Integer.parseInt(number);
        Object o = Block.blockRegistry.getObjectForID(id);
        if (o != null && o instanceof Block) {
            String fullKeyRebuild = PF172Helper.nameOf((Block) o) + (endOfNumber == key.length() ? "" : key.substring(endOfNumber));
            super.register(fullKeyRebuild, value);
            PFLog.debug("Adding legacy key: " + fullKeyRebuild + " for " + key);
        } else {
            super.register(key, value);
        }
    } catch (NumberFormatException e) {
        super.register(key, value);
    }
}

[Buggy Hunk]
Object o = Block.blockRegistry.getObjectForID(id);

[Patch]
Object o = Block.blockRegistry.getObjectById(id);

[Demonstration 2]

[Buggy Method]
@Override
public boolean canConvert(Object o) {
    return o instanceof String;
}

[Buggy Hunk]
return o instanceof String;

[Patch]
return o instanceof String || o == null;

[Demonstration 3]

[Buggy Method]
public String createKey(String p, String ns, String local) {
    StringBuilder builder = new StringBuilder();
    String jns = getJSONNamespace(ns);
    if (jns != null && jns.length() != 0) {
        builder.append(jns).append('.');
    }
    return builder.append(local).toString();
}

[Buggy Hunk]
StringBuilder builder = new StringBuilder();

[Patch]
StringBuffer builder = new StringBuffer();