G-19 with an external trigger-block style safety.
Glock makes a number of interesting variants for non-US markets. Some occasionally make it here in limited quantities.
Topical to your querstion: https://www.m4carbine.net/showthread.php?t=60116
Thanks for the link. I did get some more info, through a friend of mine who happened to be on the phone with Glock yesterday, that this was a special run of pistols for the Jordanians. Which makes sense as that was where I came across the pistol pictured.