From a6ec77a6c00b5c0a5164dc21c8f6482ea24fd06d Mon Sep 17 00:00:00 2001
From: rfranke <rfranke@users.noreply.github.com>
Date: Mon, 21 Jun 2021 15:46:56 +0200
Subject: [PATCH] Fix size of result of multiply_array in Cpp runtime (#7588)

Closes #7582
---
 .../cpp/Core/Math/ArrayOperations.cpp         | 11 ++++-
 testsuite/openmodelica/cppruntime/Makefile    |  1 +
 .../cppruntime/arrayOperationsTest.mos        | 46 +++++++++++++++++++
 3 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 testsuite/openmodelica/cppruntime/arrayOperationsTest.mos

diff --git a/OMCompiler/SimulationRuntime/cpp/Core/Math/ArrayOperations.cpp b/OMCompiler/SimulationRuntime/cpp/Core/Math/ArrayOperations.cpp
index c210b76d4ac..bb70af16eaa 100644
--- a/OMCompiler/SimulationRuntime/cpp/Core/Math/ArrayOperations.cpp
+++ b/OMCompiler/SimulationRuntime/cpp/Core/Math/ArrayOperations.cpp
@@ -272,12 +272,14 @@ void multiply_array(const BaseArray<T> &leftArray, const BaseArray<T> &rightArra
   size_t leftNumDims = leftArray.getNumDims();
   size_t rightNumDims = rightArray.getNumDims();
   size_t matchDim = rightArray.getDim(1);
-  resultArray.setDims(leftArray.getDims());
   if (leftArray.getDim(leftNumDims) != matchDim)
     throw ModelicaSimulationError(MODEL_ARRAY_FUNCTION,
                                   "Wrong sizes in multiply_array");
   if (leftNumDims == 1 && rightNumDims == 2) {
     size_t rightDim = rightArray.getDim(2);
+    vector<size_t> dims;
+    dims.push_back(rightDim);
+    resultArray.setDims(dims);
     for (size_t j = 1; j <= rightDim; j++) {
       T val = T();
       for (size_t k = 1; k <= matchDim; k++)
@@ -287,6 +289,9 @@ void multiply_array(const BaseArray<T> &leftArray, const BaseArray<T> &rightArra
   }
   else if (leftNumDims == 2 && rightNumDims == 1) {
     size_t leftDim = leftArray.getDim(1);
+    vector<size_t> dims;
+    dims.push_back(leftDim);
+    resultArray.setDims(dims);
     for (size_t i = 1; i <= leftDim; i++) {
       T val = T();
       for (size_t k = 1; k <= matchDim; k++)
@@ -297,6 +302,10 @@ void multiply_array(const BaseArray<T> &leftArray, const BaseArray<T> &rightArra
   else if (leftNumDims == 2 && rightNumDims == 2) {
     size_t leftDim = leftArray.getDim(1);
     size_t rightDim = rightArray.getDim(2);
+    vector<size_t> dims;
+    dims.push_back(leftDim);
+    dims.push_back(rightDim);
+    resultArray.setDims(dims);
     for (size_t i = 1; i <= leftDim; i++) {
       for (size_t j = 1; j <= rightDim; j++) {
         T val = T();
diff --git a/testsuite/openmodelica/cppruntime/Makefile b/testsuite/openmodelica/cppruntime/Makefile
index fea2279c1d4..e197fbef081 100644
--- a/testsuite/openmodelica/cppruntime/Makefile
+++ b/testsuite/openmodelica/cppruntime/Makefile
@@ -5,6 +5,7 @@ tearnonlin1.mos \
 WhenStatement1.mos \
 WhenTuple.mos \
 BouncingBall.mos \
+arrayOperationsTest.mos \
 arraySliceTest.mos \
 clockedAlgloopTest.mos \
 clockedEventTest.mos \
diff --git a/testsuite/openmodelica/cppruntime/arrayOperationsTest.mos b/testsuite/openmodelica/cppruntime/arrayOperationsTest.mos
new file mode 100644
index 00000000000..b4a6d7c126f
--- /dev/null
+++ b/testsuite/openmodelica/cppruntime/arrayOperationsTest.mos
@@ -0,0 +1,46 @@
+// name: arrayOperationsTest
+// keywords: array operations
+// status: correct
+// teardown_command: rm -f *ArrayOperations.Test*
+// cflags: -d=-newInst
+
+setCommandLineOptions("+simCodeTarget=Cpp");
+
+loadString("
+package ArrayOperations
+model Test
+  input Real u = 0;
+  Real y = f({u + 1, u + 2, u + 3});
+  annotation(experiment(StopTime = 0));
+end Test;
+function f
+  input Real[:] v;
+  output Real y;
+protected
+  Real[:,:] m;
+algorithm
+  // see e.g. Modelica.Mechanics.MultiBody.Examples.Rotational3DEffects.MovingActuatedDrive
+  m := matrix(v) * transpose(matrix(v));
+  y := m[3,1];
+end f;
+end ArrayOperations;
+");
+getErrorString();
+
+simulate(ArrayOperations.Test);
+getErrorString();
+
+val(y, 0);
+
+// Result:
+// true
+// true
+// ""
+// record SimulationResult
+//     resultFile = "ArrayOperations.Test_res.mat",
+//     simulationOptions = "startTime = 0.0, stopTime = 0.0, numberOfIntervals = 500, tolerance = 1e-06, method = 'dassl', fileNamePrefix = 'ArrayOperations.Test', options = '', outputFormat = 'mat', variableFilter = '.*', cflags = '', simflags = ''",
+//     messages = ""
+// end SimulationResult;
+// ""
+// 3.0
+// endResult