BUG: index error when parsing integers from prefix_rayId_lambdaId

src/thermophysicalModels/radiation/radiationModels/fvDOM/fvDOM/fvDOM.C

@@ -530,11 +530,11 @@ void Foam::radiation::fvDOM::setRayIdLambdaId
     label& lambdaId
 ) const
 {
-    // assuming name is in the form: CHARS_rayId_lambdaId
+    // Assuming name is in the form: CHARS_rayId_lambdaId
     const auto i1 = name.find('_');
-    const auto i2 = name.rfind('_');
+    const auto i2 = name.find('_', i1+1);
 
-    rayId = readLabel(name.substr(i1+1, i2-1));
+    rayId    = readLabel(name.substr(i1+1, i2-i1-1));
     lambdaId = readLabel(name.substr(i2+1));
 }