As early as 1933, the Nazis who had come into government up to that point tried to influence the legislation in Danzig negatively and to weaken the rule of law in the Free State. In contrast, the British went to the Permanent International Court of Justice in The Hague:

Ruling Series A/B65
https://www.icj-cij.org/files/publications/the-permanent-court-of-international-justice-en.pdf
The procedure can be found on page 160 of this pdf.
(Excerpt with German translation in the right column)

Article 1 - Creation of rights through appropriate application of criminal law.
"Sections 2 and 2a of the Criminal Code shall be replaced by the following
Section 2 - Punishment shall be imposed on anyone who commits an act which the law declares punishable or which deserves punishment in accordance with the fundamental principles of a criminal law and in accordance with sound public sentiment. If no specific criminal law is directly applicable to the act, the act shall be punished in accordance with the law whose basic idea best applies to it.

This amendment to § 2 StGB was rejected by the Permanent International Court of Justice in The Hague in 1935.

The advisory opinion given by the Court was to the effect that the Decrees would transfer to the judge an important function which the Constitution intended to reserve to the law, so as to safeguard individual liberty from any arbitrary encroachment on the part of the authorities of the State, and accordingly that they were not consistent with the Constitution of Danzig.

The version of Article 2 of the Criminal Code still in force today:
 
§ 2 Temporal validity
(1) The punishment and its secondary consequences shall be determined by the law applicable at the time of the offence.
(2) If the threat of punishment is changed during the commission of the offence, the law in force at the time the offence was committed shall apply.
(3) If the law in force at the time the offence is ended is changed before the decision is made, the mildest law shall apply.
(4) A law which is intended to apply only for a certain period of time shall be applied to acts committed during its validity even if it has ceased to be in force. This shall not apply if a law provides otherwise.
(5) Paragraphs 1 to 4 shall apply accordingly to forfeiture, confiscation and rendering unusable.
(6) Unless otherwise provided for by law, the decision on measures of rectification and security shall be made in accordance with the law applicable at the time of the decision.
 
So the punishability is determined exclusively by the law! - And not according to an undefined popular feeling (possibly with racist ideas......) or what kind of undefined basic idea of a judge, who perhaps has racist views, should that be???
 
Now everyone can ask himself once, which law is actually applied.