I got into the habit of keeping a bent stick wedged in the fence so that I could reach through the mesh and open the latch. But the dogs soon noticed the stick and took to snitching it, chewing into micro pieces. Then a friend gave me the solution.....a wee bit of string. It works perfectly everytime!
The latch is a standard garden gate latch from a hardware store. It already came with a hole on the latch handle, but if it hadn't, it would be simple to drill one there. I run the string, in this case a piece of electric fence string (which hardly ever breaks), through the hole and around the post that the latch is mounted on.
From the backside the string looks like this (above photo).
From a side photo, you can see that the string is run around the post so that it is a bit higher than the latch, maybe 3 inches.
To use the string to open the closed gate latch from inside the pen, I simply pull up on the string. Wallah! Latch opens and I'm not trapped.
From the outside you can see that the string pulled the handle up, opening the latch.
When you let go of the string in normal use, the latch drops back into place. But of course I've already pushed the door open a bit so that I'm not locked in still.
What a simple solution!