From 2c87e1330f0b7210d5015f8a6fbaf3b2bbe8f7b4 Mon Sep 17 00:00:00 2001
From: Yousef Moazzam <yousef.moazzam@diamond.ac.uk>
Date: Thu, 15 Oct 2026 15:19:28 +0100
Subject: [PATCH] Call setter only when technique has changed

If the technique toggle is clicked such that the technique isn't changed
(ie, the technique toggle button corresponding to the already selected
technique is clicked), `null` is the new value from the change handler,
which causes the technique to be set to `null`, and crashes the app when
the technique value is attempted to be turned to a string with all lower
case characters (the `toLowerCase()` is present on strings but not on
`null`).
---
 .../src/components/ProcessingView/TechniqueSelector.tsx       | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/frontend/unified/src/components/ProcessingView/TechniqueSelector.tsx b/frontend/unified/src/components/ProcessingView/TechniqueSelector.tsx
index fbeb76ea..f15af0af 100644
--- a/frontend/unified/src/components/ProcessingView/TechniqueSelector.tsx
+++ b/frontend/unified/src/components/ProcessingView/TechniqueSelector.tsx
@@ -35,7 +35,9 @@ const TechniqueSelector = ({
     _: React.MouseEvent<HTMLElement>,
     newTechnique: Technique
   ) => {
-    setTechnique(newTechnique);
+    if (newTechnique) {
+      setTechnique(newTechnique);
+    }
   };
   return (
     <Stack direction="column" spacing={1}>