When I download the current Adobe flash player installer from the Adobe website using Safari 6.0.1 under OSX 10.8.2, I end up with a file named 'install_flash_player_osx.dmg.mdlp' in my downloads folder. I am curious as to why the .mdlp extension is being added to the disk image containing the flash player installer, which has always terminated with the .dmg extension in the past.
The only program which uses the .mdlp extension that I am aware of is matlab; matlab is installed on this machine and it is the program the OS would like to use to open the file. I have not seen OSX, or any component thereof, replace or append file extensions in the past and I am able to download .dmg files from other websites without this phenomenon occurring.
Note that I am not interested in suggestions regarding the opening of the file, but rather an explanation as to why the .mdlp extension is being applied in the first place, whether it be by the local machine or Adobe.
Best Answer
To fix this, just rename the file to not have the .mdlp extension, i.e. it ends in .dmg. Then, do get info on the .dmg file and change the "open with" to diskimagemounter, which should now be on the list of choices.