Well, I started this new thread because it is really about how to programmatically interact with the ESP8266 WebUpdater service without using a web browser...
My task set out in the original thread you linked to is completed, i.e. I can use a TCP config service on the ESP from my custom application to read and write the config items and store them to EEPROM on command. This works very well.
And I can use a web browser to update the flash code. This also works fine.
But I thought it to be proper to integrate the firmware update function into the config application and this is my current hurdle. I am good with all the other stuff.
When I simulate the action that takes place when one hits the "Update" button on the web form presented by WebUpdater the ESP does not react as it does when I do the same from the web browser. I only get the "sleep disable" message on the debug serial line and then nothing more.
I have tried various tricks but none works all the way.
So I thought I could ask if someone knows about a non-browser solution to send flash updates to the ESP.