When I select various same-named folders in FlatViewGrouped and move them to the Destination Lister where a folder with the same name already exists, i'm missing the (overwrite or merge) confirmation dialogue.
"Ask for confirmation before merging existing folders" is checked.
Actually it's independent of FlatViewMode. check this:
When i do copy&paste i get the expected message:
When i use the "Copy"-button instead, i also get that message. But when i use the "Move"-button instead, i dont get the message and I would only get (over write confirmation messages about same-named files..
Bug?
Apart from post#2, let's go back to the original problem (post#1):
Let's assume that Destination Lister has an empty folder /folderXXX/ and we are inside this folder. The Dest Lister doesnt show anything because folderXXX is empty.
When i'm in the Source Lister in FlatViewMode(Grouped) and select several folders (=subfolders, of course!) which are all same-named, say "/folder1/", and i select them and then hit the "Move"-button, then i would still expect the Folder Merge Confirmation dialogue box to appear (because several /folder1/-folders are merged in the Dest Lister!).
When I move, i certainly get this box:
...but i dont get the merge confirmation box (of post#2).
Please confirm my observations (post#1, post#2, post#3), thanks.
In post#3, i certainly click the "Same Folder"-button. Here, "Same Folder" refers to /folderXXX/, of course. Then the first /folder1/ is moved, such that we get /folderXXX/folder1/.
Then the second /folder1/ is moved. And as such a named folder already exists in /folderXXX/ i should get the merge conf dial box.
The cirumstance when the above happens is:
When you use the folder tree and the focus is (still) on the folder in the Folder Tree rather than in the "white area" of the lister (=the contents of the folder)!
You can quickly reproduce the behavior, for example by:
(step1) create two test folders:
/folder1/folder2/., with . = {file1, file2, file3}
/folder3/folder2/., with . = {file4, file5, file6}
(step2)
go into folder3, select folder2, and press "Ctrl + x" (Cut)
(step3)
use the left-hand folder tree (Folder Tree) to select folder1. folder1's contents will automatically display in the lister. now dont click on the white area in the lister but leave the focus on the selected item (=the folder "folder1" in the Folder Tree).
(step4)
press "Ctrl + v" (Paste)
(step5)
Can i get some icecream now for all my fine contributions to this site (and finally the bug fixing of dopus)? 
I'm not sure that all of those are wrong. e.g. What should happen with flatview when two source folders are merged into a destination folder that didn't previously exist is debatable. My feeling is that the Merge warning is to stop you accidentally changing a destination folder you did not realise was there, but I don't know what the 'true' purpose of it is.
I do agree that the option to display a Merge dialog should probably apply to Move as well as Copy if it is turned on. (Whether it doesn't by design, I can't say, since I didn't design it. 
But it does seem unlikely someone would want it for copy but not move.)
Have you reported any of this to GPSoftware? I expect nobody has replied here because nobody at the forum had anything much to add.
i have filed a support ticket for this entire thread (filed under #427482415). In post#5, it's true that "Ctrl + c"&"Ctrl + v" generate the expected MERGE-dialogue whereas the exemplified "Ctrl + x"&"Ctrl + v" does not generate any expected MERGE-dialogue when using the Folder Tree focus (as emphasized in post#5).
the flat view mode behaviour (treated in posts#1-4), that's another story.. Anyway, here too i certainly expect a MERGE-dialogue by design.
Personally, i feel bad when my expectations dont get met 
I havent heard yet from GPSoftware Support 
(...)
For every reader's information I just redid the test of post#5 and can re-confirm: there is no MERGE warning message.
Then i redid the same MOVE operation with explorer.exe. As soon as i hit "ctrl + v", i get the typical Windows warning dialogue, as expected.
So there is a difference in issuing MERGE warning dialogues between Windows (expected) and Dopus (unexpected). Maybe it is by design but i would need a detailed explanation of this unexpected behaviour (since even leo agrees with me 
). Without explanation or justification i will continue to believe that this is a mean bug 
...and will test if the bug still exists in updated versions..
Please be patient. The person who wrote the merge-warning code is on holiday at the moment, and he's the best person to give a detailed explanation of it and/or change the code.
There's no need to add further detail/tests to the thread, or compare against what Explorer does (which is unrelated; Opus does not call Explorer to copy files). I think everything is clear enough as it is.