Path cleanups

[ccoffing]

Just a collection of path cleanups I have stumbled across. I have touch-tested the changes and they seem fine, except that screen won't exit (maybe it crashes) but it does that on master too.

So I think this is good as is, but screen could use some proofreading.

[tyama501]

Hi @ccoffing ,

I have been using "screen" on PC-98 and I can exit(kill?) it by Ctrl-a, k.
Can you exit by it?

Thank you.

[ccoffing]

Hi @ccoffing ,

I have been using "screen" on PC-98 and I can exit(kill?) it by Ctrl-a, k. Can you exit by it?

Thank you.

Yes, Ctrl-a k causes screen to exit. However, that returns me to the login prompt, which seems strange (I would have expected to be returned to the shell which I had started screen from.)

But the problem I originally encountered was if I typed exit from the last shell in screen. I get no further output. The machine seems to hang at that point.

[ghaerr]

Thanks @ccoffing.

However, that returns me to the login prompt, which seems strange (I would have expected to be returned to the shell which I had started screen from.)

But the problem I originally encountered was if I typed exit from the last shell in screen. I get no further output. The machine seems to hang at that point.

Both of these sound like possible stack or heap overflow. I notice that screen/Makefile already has -maout-heap=0x7000, perhaps that should be set to -maout-stack=8192 -maout-heap=0xffff to set 8K stack and max heap, to see if that changes anything. The screen source should be scrutinized to determine a max stack (default 4K) and minimum heap size.

I've been meaning to add a debug malloc (work in progress) to allow better runtime checking and reporting of these kinds of things...

[ghaerr]

/bin/sh is also tight on heap, although running screen shouldn't affect that issue. I sometimes login as toor and run from /bin/sash as an alternative for getting more input on these kinds of problems. In general, I believe both bash and sash to be pretty bug-free, so the stack overflow or memory overwrite is likely in screen.