Check duplicate issues.

• Checked for duplicates

Description

Taking a Snapshot of a dataframe with FromNumpy only works if a new column is created using Define where all the Numpy arrays passed to FromNumpy are used as inputs to the new column. Performing a Snapshot of the dataframe directly, without creating a new column, or creating a new column that does not use all the dataframe columns as inputs results in a segmentation fault. The python script in the reproducer illustrates the three cases described above.

Reproducer

import ROOT
import numpy

x, y = numpy.array([1, 2, 3]), numpy.array([4, 5, 6])
df = ROOT.RDF.FromNumpy({"x": x, "y": y})
 
# Uncomment one of the lines below to test the three different cases from the description

df.Define("z", "x + y").Snapshot("tree", "file.root") # this works
# df.Define("z", "2 * x").Snapshot("tree", "file.root") # gives a segmentation violation
# df.Snapshot("tree", "file.root") # gives a segmentation violation

ROOT version

Any

Installation method

Any

Operating system

Any

Additional context

No response