[screen-devel] [PATCH] Send resize events to attached ptys

[Alyssa Ross]

Virtual machine monitor programs like QEMU[1] and cloud-hypervisor[2]
support creating ptys which are hooked up to the VM's console.  In the
case of cloud-hypervisor, this even supports resizing, where resize
events on the pty will be propagated to the guest VM.

But when attaching to one of these ptys with screen, like
`screen /dev/pts/1`, screen wouldn't inform the pty of its output size.
We fix this by removing the pid check.  Also, we need to remove the 0
checks for the previous width and height, or screen won't resize the
pty when it first attaches, only on subsequent resizes.

[1]: https://www.qemu.org/
[2]: https://github.com/cloud-hypervisor/cloud-hypervisor
---
 src/resize.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/resize.c b/src/resize.c
index 070d3ed..686e02d 100644
--- a/resize.c
+++ b/resize.c
@@ -983,8 +983,7 @@ int wi, he, hi;
 
   /* signal new size to window */
 #ifdef TIOCSWINSZ
-  if (wi && (p->w_width != wi || p->w_height != he)
-      && p->w_width != 0 && p->w_height != 0 && p->w_ptyfd >= 0 && p->w_pid)
+  if (wi && (p->w_width != wi || p->w_height != he) && p->w_ptyfd >= 0)
     {
       glwz.ws_col = wi;
       glwz.ws_row = he;
-- 
2.32.0