When i copy a file in a folder that is allready a file with the same name, konqueror has an option for suggestion of a new name. When i download a file from the internet and i want to save it in a folder that has allready a file with the same name i dont have the option with a new filename suggestion. I am not sure but i think there was this option in previous versions of konqueror (i have the 4.5.5) and i see it in rekonq too.

I think this is only triggered on drag-and-drop. It is under the control of kio. I think the difference is when downloading a file you have a dialog that will warn you if the name is the same, so you can make a new one. Having an option to rename it automatically might be good, though.

i reported a bug because i am almost sure that this was present in previous versions
https://bugs.kde.org/show_bug.cgi?id=264037