I am not sure what to search for. I have used emacs for 25+ years, but I am not a guru. I use it as a tool, and I don't want to spend much time changing it.
I generally like to have one window, or two windows that are each half height. I don't like it when some command or mode changes the height of one of the windows to more or less than half.
For example, when I'm in a shell buffer and use tab completion, the buffer with completion options changes the window sizes, and I have to manually restore them to a 50-50 split.
I seem to remember fixing this in the past, but I don't remember how. I don't know what command or mode is doing this now, but seems to be very often since the last major release. Can someone fix this or tell me how?
Sorry if my tone is not pleasant. This is pissing me off much more than it should.