Sort of fixing actually
Update: As of GIMP 2.6, this feature is inbuilt. Select whichever portion you want to create a new image with, and then after copy/cut via Ctrl+c or Ctrl+x, just do Ctrl+Shift+v to paste into a new image based on the selection’s size in the clipboard.
As you might have seen in GIMP (2.2 and below) and Photoshop, when you copy an image to the clipboard (Ctrl + C or Ctrl + X) and create a new file via (File -> New) the size shown there automatically adjusts itself to the size of the image in the clipboard.
This feature was missing from the latest GIMP release (2.4). The reasons for that may be found here, but IMO its a bad thing this can’t be supported anymore, I heavily relied on it for one
Now on to fixing this issue:
My approach, like others, is to rely on hotkeys. In the following guide, I make a shortcut of the required function by mapping it to the [Y] key on the keyboard.
First off, the feature we’re looking for is the ‘Paste as new image‘ feature found under Edit menu of the working image.
Now to set a hotkey, use the guide below:
1. Go to File > Keyboard Shortcuts.
2. Expand the Edit menu and click and set the accelerator for “Paste as New” as [Y] or any key you wish (Must not conflict with other ones).
3. You’re done!
Now when you copy an area in an image and need to create a new file of that size you copied, just hit the [Y] key and it should do the task.
P.s. In case you screw up the hotkey settings, just remember to revert to defaults, don’t panic.