1 files changed, 7 insertions, 4 deletions
diff --git a/lib/Solver/STPSolver.cpp b/lib/Solver/STPSolver.cpp
index 8858e83e..7df61834 100644
--- a/lib/Solver/STPSolver.cpp
+++ b/lib/Solver/STPSolver.cpp
@@ -95,7 +95,7 @@ public:
   explicit STPSolverImpl(bool useForkedSTP, bool optimizeDivides = true);
   ~STPSolverImpl() override;
 
-  char *getConstraintLog(const Query &) override;
+  std::string getConstraintLog(const Query &) override;
   void setCoreSolverTimeout(time::Span timeout) override { this->timeout = timeout; }
 
   bool computeTruth(const Query &, bool &isValid) override;
@@ -195,7 +195,7 @@ STPSolverImpl::~STPSolverImpl() {
 
 /***/
 
-char *STPSolverImpl::getConstraintLog(const Query &query) {
+std::string STPSolverImpl::getConstraintLog(const Query &query) {
   vc_push(vc);
 
   for (const auto &constraint : query.constraints)
@@ -208,7 +208,10 @@ char *STPSolverImpl::getConstraintLog(const Query &query) {
   vc_printQueryStateToBuffer(vc, builder->getFalse(), &buffer, &length, false);
   vc_pop(vc);
 
-  return buffer;
+  std::string result = buffer;
+  std::free(buffer);
+
+  return result;
 }
 
 bool STPSolverImpl::computeTruth(const Query &query, bool &isValid) {
@@ -432,7 +435,7 @@ SolverImpl::SolverRunStatus STPSolverImpl::getOperationStatusCode() {
 STPSolver::STPSolver(bool useForkedSTP, bool optimizeDivides)
     : Solver(std::make_unique<STPSolverImpl>(useForkedSTP, optimizeDivides)) {}
 
-char *STPSolver::getConstraintLog(const Query &query) {
+std::string STPSolver::getConstraintLog(const Query &query) {
   return impl->getConstraintLog(query);
 }