diff --git a/.gitignore b/.gitignore
index 0065262e93d91..631ff0fbb1425 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,6 +26,9 @@ etc/allDict.h
 xcuserdata
 project.xcworkspace
 
+# MacOS metadata
+.DS_Store
+
 # Visual Code
 .vscode/*
 
diff --git a/hist/hist/src/TH1Merger.cxx b/hist/hist/src/TH1Merger.cxx
index ce4076b776e6a..92c78a57d9f1c 100644
--- a/hist/hist/src/TH1Merger.cxx
+++ b/hist/hist/src/TH1Merger.cxx
@@ -384,13 +384,13 @@ Bool_t TH1Merger::BufferMerge() {
          }
          if (fH0->fDimension == 2) {
             auto h2 = dynamic_cast<TH2*>(fH0);
-            R__ASSERT(h2); 
+            R__ASSERT(h2);
             for (Int_t i = 0; i < nbentries; i++)
                h2->Fill(hist->fBuffer[3*i + 2], hist->fBuffer[3*i + 3],hist->fBuffer[3*i + 1] );
          }
          if (fH0->fDimension == 3) {
             auto h3 = dynamic_cast<TH3*>(fH0);
-            R__ASSERT(h3); 
+            R__ASSERT(h3);
             for (Int_t i = 0; i < nbentries; i++)
                h3->Fill(hist->fBuffer[4*i + 2], hist->fBuffer[4*i + 3],hist->fBuffer[4*i + 4], hist->fBuffer[4*i + 1] );
          }
diff --git a/math/mathmore/src/GSLMultiFitFunctionWrapper.h b/math/mathmore/src/GSLMultiFitFunctionWrapper.h
index d3639bf4d2886..833f1a7801723 100644
--- a/math/mathmore/src/GSLMultiFitFunctionWrapper.h
+++ b/math/mathmore/src/GSLMultiFitFunctionWrapper.h
@@ -67,6 +67,8 @@ class GSLMultiFitFunctionWrapper {
       fFunc.n = 0;
       fFunc.p = 0;
       fFunc.params = 0;
+      fFunc.nevalf = 0;
+      fFunc.nevaldf = 0;
    }
 
 
diff --git a/math/mathmore/test/testDerivation.cxx b/math/mathmore/test/testDerivation.cxx
index 591060d5e27d2..1788d59dc37c2 100644
--- a/math/mathmore/test/testDerivation.cxx
+++ b/math/mathmore/test/testDerivation.cxx
@@ -118,7 +118,8 @@ int testDerivation() {
 //   WrappedFunc fy(*f2d,0,vx);
 //   std::cout << "df/dy  = " << der->EvalCentral(fy,2.) << std::endl;
 // #endif
-
+  delete der;       //fix memory leak
+  der = nullptr;
   return status;
 }
 
diff --git a/math/mathmore/test/testGSLRootFinder.cxx b/math/mathmore/test/testGSLRootFinder.cxx
index cb8bb343f150f..b79fc3e34a4bf 100644
--- a/math/mathmore/test/testGSLRootFinder.cxx
+++ b/math/mathmore/test/testGSLRootFinder.cxx
@@ -167,9 +167,15 @@ int testGSLRootFinder() {
   }
   timer.Stop();
   status += printStats(rf6, returnCode, timer);
-
+  delete rf1;
+  rf1 = nullptr;
+  delete rf2;
+  rf2 = nullptr;
+  delete rf3;
+  rf3 = nullptr;
+  delete rf4;
+  rf4 = nullptr;
   return status;
-
 }
 
 int main() {
diff --git a/math/mathmore/test/testInterpolation.cxx b/math/mathmore/test/testInterpolation.cxx
index 5abcc586e975c..920bdfb7c9c17 100644
--- a/math/mathmore/test/testInterpolation.cxx
+++ b/math/mathmore/test/testInterpolation.cxx
@@ -29,10 +29,14 @@ void interpolate( const  ROOT::Math::Interpolator & itp, bool drawSame = false )
 
    std::cout << "x[i]     y[i]     deriv[i]     deriv2[i]    integral[i] \n" << std::endl;
    // print result of interpolation
-   const Int_t n = 51;
+   const Int_t n = 50;  //JH replacing n = 51;
    Int_t i = 0;
+   double xi = 0.;
    Float_t xcoord[n], ycoord[n];
-   for ( double xi = 0; xi < 10.01; xi += 0.2) {
+
+   for ( i = 0; i < 50; ++i) { 
+      xi = 0.2 * i;
+      // JH replacing for ( double xi = 0; xi < 10.01; xi += 0.2) {
       xcoord[i] = xi;
       ycoord[i] = itp.Eval(xi);
       double dyi = itp.Deriv(xi);
diff --git a/test/TFormulaTests.cxx b/test/TFormulaTests.cxx
index ca4fd1d18d688..a42b041027dd3 100644
--- a/test/TFormulaTests.cxx
+++ b/test/TFormulaTests.cxx
@@ -184,6 +184,7 @@ Bool_t TFormulaTests::SetVars()
          successful = false;
       }
    }
+   delete[] vars;
    return successful;
 }
 
diff --git a/test/stressHistogram.cxx b/test/stressHistogram.cxx
index 1979016864210..eb7307e2ea514 100644
--- a/test/stressHistogram.cxx
+++ b/test/stressHistogram.cxx
@@ -10243,6 +10243,10 @@ int stressHistogram()
              << gROOT->GetGitBranch() << "@" << gROOT->GetGitCommit() << std::endl;
    std::cout <<"****************************************************************************\n";
 
+   if (cleanHistos) {
+      delete ht2;
+      delete htp2;
+   }
    return GlobalStatus;
 }
 
diff --git a/test/stressTMVA.cxx b/test/stressTMVA.cxx
index 268fb461d74ad..bde8f16af3552 100644
--- a/test/stressTMVA.cxx
+++ b/test/stressTMVA.cxx
@@ -1583,8 +1583,10 @@ bool utFactory::addEventsToFactoryByHand(const char* factoryname, const char* op
    factory->TrainAllMethods();
    factory->TestAllMethods();
    factory->EvaluateAllMethods();
-   MethodBase* theMethod = dynamic_cast<TMVA::MethodBase*> (factory->GetMethod(dataloader->GetName(), _methodTitle));
-   double ROCValue = theMethod->GetROCIntegral();
+   double ROCValue(0.);
+   if (auto theMethod = dynamic_cast<TMVA::MethodBase *>(factory->GetMethod(dataloader->GetName(), _methodTitle))) {
+      ROCValue = theMethod->GetROCIntegral();
+   }
    //cout << "ROC="<<ROCValue<<endl;
    delete dataloader; 
    delete factory;
@@ -1643,8 +1645,10 @@ bool utFactory::operateSingleFactory(const char* factoryname, const char* opt)
    factory->TrainAllMethods();
    factory->TestAllMethods();
    factory->EvaluateAllMethods();
-   MethodBase* theMethod = dynamic_cast<TMVA::MethodBase*> (factory->GetMethod(dataloader->GetName(), _methodTitle));
-   double ROCValue = theMethod->GetROCIntegral();
+   double ROCValue(0.);
+   if (auto theMethod = dynamic_cast<TMVA::MethodBase *>(factory->GetMethod(dataloader->GetName(), _methodTitle))) {
+      ROCValue = theMethod->GetROCIntegral();
+   }
    delete tree;
    delete dataloader; 
    delete factory;
diff --git a/tmva/tmvagui/src/rulevisHists.cxx b/tmva/tmvagui/src/rulevisHists.cxx
index d397e7c10594f..1edd521d1143d 100644
--- a/tmva/tmvagui/src/rulevisHists.cxx
+++ b/tmva/tmvagui/src/rulevisHists.cxx
@@ -174,6 +174,7 @@ void TMVA::rulevisHists( TDirectory *rfdir, TDirectory *vardir, TDirectory *corr
          if (bgd == NULL) {
             cout << "ERROR!!! couldn't find backgroung histo for" << hname << endl;
             //exit(1);
+            delete [] c;
             return;
          }