From f615441f069cea5a835c1302fa84f7f5a9bdf538 Mon Sep 17 00:00:00 2001
From: John Tramm <john.tramm@gmail.com>
Date: Fri, 9 May 2025 22:10:25 -0500
Subject: [PATCH] Random Ray Misc Memory Error Fixes (#3405)

Co-authored-by: Hunter Belanger <hunter.belanger@gmail.com>
---
 src/random_ray/flat_source_domain.cpp |  8 +++++---
 src/random_ray/random_ray.cpp         | 21 +++++++++++++--------
 src/random_ray/source_region.cpp      |  6 +++++-
 3 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/src/random_ray/flat_source_domain.cpp b/src/random_ray/flat_source_domain.cpp
index 8ab30abf20..cd073f3507 100644
--- a/src/random_ray/flat_source_domain.cpp
+++ b/src/random_ray/flat_source_domain.cpp
@@ -206,9 +206,11 @@ void FlatSourceDomain::set_flux_to_flux_plus_source(
   int material = source_regions_.material(sr);
   if (material == MATERIAL_VOID) {
     source_regions_.scalar_flux_new(sr, g) /= volume;
-    source_regions_.scalar_flux_new(sr, g) +=
-      0.5f * source_regions_.external_source(sr, g) *
-      source_regions_.volume_sq(sr);
+    if (settings::run_mode == RunMode::FIXED_SOURCE) {
+      source_regions_.scalar_flux_new(sr, g) +=
+        0.5f * source_regions_.external_source(sr, g) *
+        source_regions_.volume_sq(sr);
+    }
   } else {
     double sigma_t = sigma_t_[source_regions_.material(sr) * negroups_ + g];
     source_regions_.scalar_flux_new(sr, g) /= (sigma_t * volume);
diff --git a/src/random_ray/random_ray.cpp b/src/random_ray/random_ray.cpp
index 532840f1f4..27819591cd 100644
--- a/src/random_ray/random_ray.cpp
+++ b/src/random_ray/random_ray.cpp
@@ -518,8 +518,10 @@ void RandomRay::attenuate_flux_flat_source_void(
   }
 
   // Add source to incoming angular flux, assuming void region
-  for (int g = 0; g < negroups_; g++) {
-    angular_flux_[g] += srh.external_source(g) * distance;
+  if (settings::run_mode == RunMode::FIXED_SOURCE) {
+    for (int g = 0; g < negroups_; g++) {
+      angular_flux_[g] += srh.external_source(g) * distance;
+    }
   }
 }
 
@@ -688,7 +690,10 @@ void RandomRay::attenuate_flux_linear_source_void(
   // transport through a void region is greatly simplified. Here we
   // compute the updated flux moments.
   for (int g = 0; g < negroups_; g++) {
-    float spatial_source = srh.external_source(g);
+    float spatial_source = 0.f;
+    if (settings::run_mode == RunMode::FIXED_SOURCE) {
+      spatial_source = srh.external_source(g);
+    }
     float new_delta_psi = (angular_flux_[g] - spatial_source) * distance;
     float h1 = 0.5f;
     h1 = h1 * angular_flux_[g];
@@ -750,8 +755,10 @@ void RandomRay::attenuate_flux_linear_source_void(
   }
 
   // Add source to incoming angular flux, assuming void region
-  for (int g = 0; g < negroups_; g++) {
-    angular_flux_[g] += srh.external_source(g) * distance;
+  if (settings::run_mode == RunMode::FIXED_SOURCE) {
+    for (int g = 0; g < negroups_; g++) {
+      angular_flux_[g] += srh.external_source(g) * distance;
+    }
   }
 }
 
@@ -782,9 +789,7 @@ void RandomRay::initialize_ray(uint64_t ray_id, FlatSourceDomain* domain)
     fatal_error("Unknown sample method for random ray transport.");
   }
 
-  site.E = lower_bound_index(
-    data::mg.rev_energy_bins_.begin(), data::mg.rev_energy_bins_.end(), site.E);
-  site.E = negroups_ - site.E - 1.;
+  site.E = 0.0;
   this->from_source(&site);
 
   // Locate ray
diff --git a/src/random_ray/source_region.cpp b/src/random_ray/source_region.cpp
index 6c0df0157f..69541f7f8e 100644
--- a/src/random_ray/source_region.cpp
+++ b/src/random_ray/source_region.cpp
@@ -217,7 +217,11 @@ SourceRegionHandle SourceRegionContainer::get_source_region_handle(int64_t sr)
   handle.scalar_flux_old_ = &scalar_flux_old(sr, 0);
   handle.scalar_flux_new_ = &scalar_flux_new(sr, 0);
   handle.source_ = &source(sr, 0);
-  handle.external_source_ = &external_source(sr, 0);
+  if (settings::run_mode == RunMode::FIXED_SOURCE) {
+    handle.external_source_ = &external_source(sr, 0);
+  } else {
+    handle.external_source_ = nullptr;
+  }
   handle.scalar_flux_final_ = &scalar_flux_final(sr, 0);
   handle.tally_task_ = &tally_task(sr, 0);