Fix TF1::DrawCopy issue

[couet]

TF1::Copy didn't copy fHistogram if it exited.
It fixes this issue: #13122

[dpiparo]

BP to 636 when all tests are passing?

[couet]

It needs more checks. It does not work yet.

[ferdymercury]

It needs more checks. It does not work yet.

Interesting. I thought that copy-pasting

   if (fHistogram) {
      obj->fHistogram = (TH1*)fHistogram->Clone();
      obj->fHistogram->SetDirectory(nullptr);
   }

as done in TF1::Clone should do the job.

[ferdymercury]

Thanks a lot!

Could you add this gtest?

TEST(TF1, DrawCopy)
{
   auto f = new TF1("fa1","x*x",-3,3);
   f->GetXaxis()->SetTitle("xtitle");
   auto fcopy = f->DrawCopy();
   EXPECT_EQ(fcopy->GetXaxis()->GetTitle(), "xtitle");
}

[couet]

indeed I am on it

[github-actions]

Test Results

    21 files      21 suites   3d 6h 6m 57s ⏱️
 3 377 tests  3 375 ✅ 0 💤 2 ❌
69 188 runs  69 182 ✅ 0 💤 6 ❌

For more details on these failures, see this check.

Results for commit 6a4bf66.

♻️ This comment has been updated with latest results.

[ferdymercury]

Thanks a lot! LGTM

[couet]

It looks like the failures are not related to this PR

[ferdymercury]

Looks ready to merge, thanks!!