I cast all my spells from the keyboard and always found myself hitting alt+shift+home ctrl+c before a pull to save when I have half typed so I can paste it back then I get a chance to finish it up. What I wanted to see is when you hit escape to close the editbox that it would not clear and when you brought it back by hitting enter it would still have its contents.
I have created a patch that adds this feature. The only problem I can see with this patch is that I hooked ChatFrame_OpenChat so now any call to it with an empty string will recall the old text if there is any. I tried to make this work without hooking ChatFrame_OpenChat but macro text was being recalled when hitting enter after running a macro.
I hope other keyboard players would also find this useful.