From f6004908c322e14f6b806890e9829294b4925077 Mon Sep 17 00:00:00 2001
From: Alyssa Ross <hi@alyssa.is>
Date: Sun, 19 Sep 2021 11:15:10 +0000
Subject: screen: send resize events to attached ptys

---
 .../0001-Send-resize-events-to-attached-ptys.patch | 39 ++++++++++++++++++++++
 pkgs/tools/misc/screen/default.nix                 |  4 +++
 2 files changed, 43 insertions(+)
 create mode 100644 pkgs/tools/misc/screen/0001-Send-resize-events-to-attached-ptys.patch

diff --git a/pkgs/tools/misc/screen/0001-Send-resize-events-to-attached-ptys.patch b/pkgs/tools/misc/screen/0001-Send-resize-events-to-attached-ptys.patch
new file mode 100644
index 00000000000..44d66137dbb
--- /dev/null
+++ b/pkgs/tools/misc/screen/0001-Send-resize-events-to-attached-ptys.patch
@@ -0,0 +1,39 @@
+From 0a083af3274639416ca7a8a7bb260d886110080f Mon Sep 17 00:00:00 2001
+From: Alyssa Ross <hi@alyssa.is>
+Date: Sun, 19 Sep 2021 11:05:32 +0000
+Subject: [PATCH] Send resize events to attached ptys
+
+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
+
diff --git a/pkgs/tools/misc/screen/default.nix b/pkgs/tools/misc/screen/default.nix
index 884d5317cb8..5f2b95b6f87 100644
--- a/pkgs/tools/misc/screen/default.nix
+++ b/pkgs/tools/misc/screen/default.nix
@@ -16,6 +16,10 @@ stdenv.mkDerivation rec {
     "--enable-colors256"
   ];
 
+  patches = [
+    ./0001-Send-resize-events-to-attached-ptys.patch
+  ];
+
   nativeBuildInputs = [
     autoreconfHook
   ];
-- 
cgit 1.4.1