[DF] Add a unit test to check jitted filters

Author: ikabadzhov

tree/dataframe/test/dataframe_interface.cxx

@@ -859,3 +859,21 @@ TEST(RDataFrameInterface, RedefineFriend)
    auto sum = df.Redefine("friend.x", [](int _x) { return _x + 1; }, {"friend.x"}).Sum<int>("friend.x");
    EXPECT_EQ(*sum, 43);
 }
+
+// #11002
+TEST(RDataFrameUtils, RegexWithFriendsInJittedFilters)
+{
+   TTree t("t", "t");
+   int x = 42;
+   t.Branch("x", &x);
+   t.Fill();
+   TTree fr("fr", "fr");
+   x = -42;
+   fr.Branch("x", &x);
+   fr.Fill();
+   t.AddFriend(&fr);
+   ROOT::RDataFrame df(t);
+   // ensure that order of operations does not matter
+   EXPECT_EQ(df.Filter("fr.x < 0 && x > 0").Count().GetValue(), 1);
+   EXPECT_EQ(df.Filter("x > 0 && fr.x < 0").Count().GetValue(), 1);
+}