Created attachment 1191400 [details]
Makefile for clip.c.

gtk_clipboard_set_with_data does not function properly when executed GNOME on Wayland.  The attached clip.c functions properly when on GNOME.   The attacted test code using gtk_clipboard_set_with_data to set clipboard sequentially with multiple targets with one function call. A Makefile is attached for clip.c.  When running under Wayland the "get" function is not called when clipboard is pasted after the  first call.  On very rare occasions the "get" function is called after the first paste under Wayland.

Under GNOME:

$ ./clip Three Two One
Paste clipboard contents into gedit, One is displayed in gedit.
The following is output on terminal.
get One
Paste clipboard contents into gedit, Two is displayed in gedit.
The following is output on terminal.
get Two
Paste clipboard contents into gedit, Three is displayed in gedit.
The following is output on terminal.
get Three
My work is done.

Under GNOME on Wayland

$ ./clip Three Two One
Paste clipboard contents into gedit, One is displayed in gedit.
The following is output on terminal.
get One
Paste clipboard contents into gedit, One is displayed in gedit again.
No message printed on terminal.
Paste clipboard contents into gedit, One is displayed in gedit again.

Each paste continues to display One. 

And sometimes you get a Two with get Two output on the terminal.

The results are very erratic.

This is not a Wayland bug.  I found that some applications don't work the same in Fedora 24 Wayland compared to Fedora 24 X11.  Firefox and google-chrome work Ok but gedit does not.  Closing.

Not sure if this really is "notabug" or simply a bug is some other component. As a rule of thumb, it's hardly ever a "Wayland" bug per se.

In Wayland as a whole, you have the Wayland protocols (XML based specifications), the Wayland library (either client or server, low-level libraries unrelated to high level user features such as clipboard management), the Wayland compositor (mutter/gnome-shell in GNOME), the toolkit (gtk+ for GNOME) and the applications.

The vast majority of "Wayland" bugs reside in either the compositor, the toolkit or the applications.

Add to this the applications that are not ported to Wayland and still run in X11 and therefore rely on Xwayland (that's the case for Firefox and google-chrome at this time of writing) and you have an additional candidate for bugs which is Xwayland.

The tricky part is to find the right component among those 4 candidates for bugs.

I changed the status from CLOSED to MODIFIED.  Hope this OK.

This is a bug related to Wayland.  

gtk_clipboard_set_with_data's get function is not being called when it should be called.  It is called properly the first time but should be called again after each paste.  If you change the focus from the application after each paste it is called.  That is not correct based on the way it works in X11. The following steps show the difference.

In Fedora 25 alpha login with X11.

Run test program clip.

$ ./clip Three Two One

Run gedit.

Right Click and Paste into gedit 3 times.

In gedit:

OneTwoThree

On terminal:

get One
get Two
get Three
My work is done.

The above is the expected behavior using the
gtk_clipboard_set_with_data function.

In Fedora 25 alpha login with Wayland.

$ ./clip Three Two One

Run gedit.

Right Click and Paste into gedit 3 times.

In gedit:

OneOneOne

On terminal:

get One

In Wayland the get function in the test program
was called only once and the clipboard contained
the same data for the three pastes.

In Fedora 25 alpha login with Wayland.

$ ./clip Three Two One

Run gedit.

Perform 1,2 and 3 for three pastes.

1. Right Click and Paste.
2. Change the focus from gedit to another window.
3. Change focus back to gedit.

In gedit:

OneTwoThree

On terminal:

get One
get Two
get Three
My work is done.

Something is blocking the call to the get function
until the focus is changed from the gedit window.

This test can be run using Firefox instead of gedit
with the same results.

gtk_clipboard_set_with_data does not function properly in Wayland in Fedora 25 Beta.

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