How would the law handle a &quot;merge conflict&quot;?
<p>Imagine this scenario:</p>

<ul>
<li>Bill A is passed, creating Law A.</li>
<li>Bill B is passed. It modifies some parts of Law A, plus it adds some laws that depend on it and some laws that do not.</li>
<li>A court rules that Bill A was not validly passed and must be repealed.</li>
</ul>

<p>(Example of the last point: the <a href="https://en.wikipedia.org/wiki/Joint_Sitting_of_the_Australian_Parliament_of_1974#Subsequent_legal_challenges" rel="nofollow noreferrer">Australian <em>Petroleum and Minerals Authority Act</em>, 1973</a>. The High Court that the bill had not been "defeated" by the Senate merely adjourning without considering it, so the requirements for holding a joint session to pass it, as Parliament had done, had not been met.)</p>

<p>Obviously the legislature would have to meet to resolve the conflict, but before it does, what is the state of the law with the valid parts of Bill B?</p>

<blockquote>
  <p>what is the state of the law with the valid parts of Bill B?</p>
</blockquote>

<p>If by "<em>valid</em>" you mean the sections which are unrelated to Bill/Law A, then they retain their status just as if the court had not stricken the unrelated legislation. </p>

<p>For instance, see <a href="https://www.leagle.com/decision/1900651179us4721601" rel="noreferrer">*Loeb v. Columbia Township Trustess, 179 US 472, 490 (1900)</a> regarding invalid sections: "<em>One part may stand, while another will fall, unless the two are so connected, or dependent on each other in subject matter, meaning or purpose, that the good cannot remain without the bad</em>".</p>

<p>This is also known as the <em>doctrine of elision</em>. See <a href="https://www.leagle.com/decision/19941702879sw2d82311697" rel="noreferrer"><em>State v. Tester</em>, 879 S.W.2d 823, 830 (1994)</a>. The doctrine is premised on "<em>there [being] enough of the act for a complete law capable of enforcement and fairly answering the object of its passage</em>" coupled with an indication that the legislative intent is "<em>to have the valid parts of the statute enforced if some other portion of the statute has been declared unconstitutional</em>". One way to evidence the latter is by including <em>a severability clause</em> in the statute, <em>Id</em>. Similarly, see <a href="https://www.leagle.com/decision/inksco20160527210" rel="noreferrer"><em>Gannon v. State</em>, 372 P.3d 1181, 1203 (2016)</a>, and <a href="https://www.leagle.com/decision/1969418222so2d1961354" rel="noreferrer"><em>Small v. Sun Oil Company</em>, 222 So.2d 196, 199 (1969)</a>.</p>

<p>You did not specify the jurisdiction you have in mind. Regardless, that jurisdiction is very unlikely to take a materially different approach to address this issue.</p>

legislative-intent