Created attachment 210273 [details]
QClipboard sometimes fails to paste the image that is present in the clipboard.
How to reproduce:
1. Compile the executable 'test' from the attached shar by running 'sh mk.sh'
2. In the Chromium browser go to https://wooda.co/wp-content/uploads/2018/02/Log-Type-E-Designer-Wooden-Chair-1.png It should display the picture of a wooden chair. With right mouse button open the menu, and select the "Copy image" item
3. Run the executable 'test'
4. It will most likely fail like this:
> $ ./test
> has image: mime= "TIMESTAMP, TARGETS, SAVE_TARGETS, MULTIPLE, image/png, text/html, application/x-qt-image"
> INVALID! height=0!
Qt says that the image in the clipboared is zero-sized. However, this X11 command pastes it without a problem:
> xclip -selection clipboard -t image/png -o > x.png
For a comparison, when I do the same in the Firefox browser Qt pastes the image fine:
> $ ./test
> has image: mime= "TIMESTAMP, TARGETS, MULTIPLE, SAVE_TARGETS, text/html, text/_moz_htmlinfo, text/_moz_htmlcontext, image/png, image/bmp, image/x-bmp, image/x-MS-bmp, image/x-icon, image/x-ico, image/x-win-bitmap, image/vnd.microsoft.icon, application/ico, image/ico, image/icon, text/ico, image/jpeg, image/tiff, application/x-qt-image"
> Valid: size= 427 x 600
Curiously, sometimes, every once in 15-20+ times, Qt is able to paste the image even when Chromium copied it into the clipboard.