From b3868102a787e7b44c1ba49d8446f5796568ec42 Mon Sep 17 00:00:00 2001
From: ferdymercury <ferdymercury@users.noreply.github.com>
Date: Thu, 21 Nov 2024 18:17:29 +0100
Subject: [PATCH] [io] warn user about the trailing blanks being stripped from
 keyname upon writing

See https://github.com/root-project/root/issues/17003
---
 io/io/src/TDirectoryFile.cxx | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/io/io/src/TDirectoryFile.cxx b/io/io/src/TDirectoryFile.cxx
index 0d4e8be9ce967..6953c660fe801 100644
--- a/io/io/src/TDirectoryFile.cxx
+++ b/io/io/src/TDirectoryFile.cxx
@@ -1946,6 +1946,8 @@ Int_t TDirectoryFile::WriteTObject(const TObject *obj, const char *name, Option_
    Int_t nch = strlen(oname);
    char *newName = nullptr;
    if (nch && oname[nch-1] == ' ') {
+      Warning("WriteTObject", "The key name '%s' will be stored in file without the trailing blanks.", obj->GetName());
+      // See https://github.com/root-project/root/issues/17003
       newName = new char[nch+1];
       strlcpy(newName,oname,nch+1);
       for (Int_t i=0;i<nch;i++) {