Confirmed:
Ubuntu 14.04 x 64
LibreOffice 4.4 built a few days ago & oldest version preBibisect - updating version

New - confirmed
Minor - slows down but doesn't prevent high quality work
Low - default seems appropriate

I see it was set to high - please don't update the importance/priority. We use a specific system that is objectively applied. Thanks for reporting!

Drag A1:C1 downwards does nothing for me, it is inactive. It works only if you drag A1:D1 that is at least one cell not merged right more.
Tested with version 4.1.6, 4.2.6.3, 4.3.4.0.0+ and 4.4.0.0.alpha1+ under Ubuntu 14.04 x86-64

I think that merging cells is not a kind of formatting. Merging cells changes the structure of the sheet when formatting does not.

Copy & paste is not intended to do the same as dragging downwards. Indeed when you drag a cell with a contents, other cells are filled with a contents updated (values incremented and formula updated) what it is not the case when you simply copy & paste (values not incremented).

So, for me, the bug description does not match the current behavior of Calc.

Please, could you explain further? 

Set status to NEEDINFO. Please set it back to UNCONFIRMED once you have provided requested informations. Thank you for your understanding.

Best regards. JBF

Hi,

This is my impression, that using the handle on a cell, a group of cells,  found in the right lower corner should equal either create a serie or if you hold down CTRL copy the content. But I might be incorrect.

(In reply to p_kongstad from comment #3)
> Hi,
> 
> This is my impression, that using the handle on a cell, a group of cells, 
> found in the right lower corner should equal either create a serie or if you
> hold down CTRL copy the content. But I might be incorrect.

Did you check, on your own system, that dragging a merged cell is actually possible?

Best regards. JBF

(In reply to Jean-Baptiste Faure from comment #4)
> (In reply to p_kongstad from comment #3)
> > Hi,
> > 
> > This is my impression, that using the handle on a cell, a group of cells, 
> > found in the right lower corner should equal either create a serie or if you
> > hold down CTRL copy the content. But I might be incorrect.
> 
> Did you check, on your own system, that dragging a merged cell is actually
> possible?
> 
> Best regards. JBF

Yes, I can drag merged cells around in the spreadsheet. But that has nothing to do with copying and copy cell downwards using the dragging method (mouse).

I am not sure if we are speaking about the same thing. I try to reword:
What I mean is that when I select the merged cells and place the mouse pointer on the black small square in the bottom right corner, the mouse pointer becomes a +, and, normally, if I hold down the left button of the mouse, I can drag downwards and the effect of this movement is to fill the cells below with its updated contents.
What I say, is that, when I try to do that with a merged cell (like A1:C1 in your description), it does not work, it does nothing. Is it the same for you ?
It works if I first drag right (to D1) then below.

Best regards. JBF

(In reply to Jean-Baptiste Faure from comment #6)
> I am not sure if we are speaking about the same thing. I try to reword:
> What I mean is that when I select the merged cells and place the mouse
> pointer on the black small square in the bottom right corner, the mouse
> pointer becomes a +, and, normally, if I hold down the left button of the
> mouse, I can drag downwards and the effect of this movement is to fill the
> cells below with its updated contents.
> What I say, is that, when I try to do that with a merged cell (like A1:C1 in
> your description), it does not work, it does nothing. Is it the same for you
> ?
> It works if I first drag right (to D1) then below.
> 
> Best regards. JBF

Yes, it works for me as you describe, but you have to drag some rows downwards before the lines becomes visible and the merged cell becomes copied, but that is due to another bug I think.

If it is 2 merged cells you have to drag downwards 5 or more. If 3 merged cells drag downwards 10 or more. Also non logical.

(In reply to p_kongstad from comment #7)
> [...]
> Yes, it works for me as you describe, but you have to drag some rows
> downwards before the lines becomes visible and the merged cell becomes
> copied, but that is due to another bug I think.
 
Ok, I reproduce this behavior. I suggest you to open a new bug report for this particular behavior.

From description:
> Expected behavior:
>
> Column A - C should be filled out as merged. Same as CTRL+C and CTRL+V

Why dragging should act as copy & paste?
I think that merging cells is not a kind of formatting. Merging cells changes the structure of the sheet when formatting does not. 
As already written, copy & paste is not intended to do the same as dragging downwards. Indeed when you drag a cell with a contents, other cells are filled with this contents updated (values incremented and formula updated). It is not the case when you simply copy & paste, values are not incremented.

For me it is not a bug but I may be wrong.

Best regards. JBF

(In reply to Jean-Baptiste Faure from comment #8)

> 
> Why dragging should act as copy & paste?
> I think that merging cells is not a kind of formatting. Merging cells
> changes the structure of the sheet when formatting does not. 
> As already written, copy & paste is not intended to do the same as dragging
> downwards. Indeed when you drag a cell with a contents, other cells are
> filled with this contents updated (values incremented and formula updated).
> It is not the case when you simply copy & paste, values are not incremented.
> 
> For me it is not a bug but I may be wrong.
> 
> Best regards. JBF

This is how other spreadsheets are working with merged cells and dragging them with the small rectangle.

So I consider this as a bug.

Maybe some one will bring other opinions to this issue. At the same time I upgrade from minor to normal.

Please do not mess around with the severity or importance. I already said that in my previous comment. By our definition this is a minor issue.

I agree that it's a bug though - when I dragged I expected the format to continue and the format includes merging.

let's set status to NEW since the bug was confirmed by other users.

Bug still present Version: 5.2.1.1
Build ID: 2d75cf29e6d05e44c404f0547047f1da6563d380
CPU Threads: 2; OS Version: Linux 4.4; UI Render: default; 
Locale: en-US (en_US.UTF-8); Calc: group

*** This bug has been marked as a duplicate of bug 59585 ***