[Affected versions]: - Firefox 53 Beta 2 - latest Aurora 54.0a2 (2017-03-15) - latest Nightly 55.0a1 (2017-03-15) [Affected platforms]: - Windows 7 x64 - Windows 10 x64 [Steps to reproduce]: 1. Start Firefox and visit https://mystor.github.io/dragndrop/. 2. Select paste-image-data from the demopage. 3. In a new window visit a webpage with many images(e.g: http://1stwebdesigner.com/image-file-types/) 4. Select an image from the website and copy it to clipboard (Right click an image and select Copy image). 5. Select Drop Stuff Here! area from demopage and paste the image copied earlier (CTRL+V). [Expected result]: - "Matching" appears under the Drop Stuff Here area, the expected result is identical to the result. [Actual result]: - "Not matching" appears under the Drop Stuff Here area. Result kind: paste types: [0] application/x-moz-file [1] Files file count: 1 items: [0] file - image/jpeg Expected Result kind: paste types: [0] text/html [1] Files file count: 1 items: [0] string - text/html [1] file - image/png [Regression range]: - TBD [Additional notes]: - This issue is reproducible only with e10s disabled.

This is probably related to bug 1308007. Namely, it appears as though copying image data on windows causes it to look like a file was copied to the clipboard, and in the non-e10s case, the file handling case takes over, while in the e10s case, the file fails to transmit to the content process, and thus we fall back to a normal image.