From 62179fb563f00b6f0e02e7880dc8d382f9744d88 Mon Sep 17 00:00:00 2001
From: Daniel Weindl <daniel.weindl@helmholtz-munich.de>
Date: Tue, 8 Oct 2024 13:43:01 +0200
Subject: [PATCH] Fix AmiVector::nvec_ for size 0

---
 include/amici/vector.h |  3 +--
 src/solver.cpp         |  2 +-
 src/vector.cpp         | 10 +++++-----
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/include/amici/vector.h b/include/amici/vector.h
index 72da7a9230..32c436fbda 100644
--- a/include/amici/vector.h
+++ b/include/amici/vector.h
@@ -88,8 +88,7 @@ class AmiVector {
             return;
         }
         nvec_ = N_VMake_Serial(
-            gsl::narrow<long int>(vold.vec_.size()), vec_.data(),
-            vold.nvec_->sunctx
+            gsl::narrow<long int>(vec_.size()), vec_.data(), vold.nvec_->sunctx
         );
     }
 
diff --git a/src/solver.cpp b/src/solver.cpp
index c4fcc72399..5c96855d97 100644
--- a/src/solver.cpp
+++ b/src/solver.cpp
@@ -769,7 +769,7 @@ void Solver::setConstraints(std::vector<realtype> const& constraints) {
 
     if (!any_constraint) {
         // all-0 must be converted to empty, otherwise sundials will fail
-        constraints_ = AmiVector();
+        constraints_ = AmiVector(0, sunctx_);
         return;
     }
 
diff --git a/src/vector.cpp b/src/vector.cpp
index 199a50b31b..78b3fe5521 100644
--- a/src/vector.cpp
+++ b/src/vector.cpp
@@ -58,11 +58,11 @@ void AmiVector::copy(AmiVector const& other) {
 void AmiVector::synchroniseNVector(SUNContext sunctx) {
     if (nvec_)
         N_VDestroy_Serial(nvec_);
-    nvec_ = vec_.empty()
-                ? nullptr
-                : N_VMake_Serial(
-                      gsl::narrow<long int>(vec_.size()), vec_.data(), sunctx
-                  );
+    if (sunctx) {
+        nvec_ = N_VMake_Serial(
+            gsl::narrow<long int>(vec_.size()), vec_.data(), sunctx
+        );
+    }
 }
 
 AmiVector::~AmiVector() {