Disable exclusive mode on TTY device when closing

When opening a TTY we enable exclusive mode to prevent other tools
messing with our connection. When we are done using the TTY the
exclusive mode must be disabled so the TTY can be reconnected to
later. We remember to do this when a break is sent to the device,
but not on window close.

This change ensures we disable exclusive mode on the TTY device
whenever the window is closed.

bug #52248

3 files changed, 20 insertions, 3 deletions

diff --git a/src/tty.c b/src/tty.c
index a6a6c90..1086be5 100644
--- a/src/tty.c
+++ b/src/tty.c
@@ -157,6 +157,14 @@ int OpenTTY(char *line, char *opt)
 	return f;
 }
 
+int CloseTTY(int fd)
+{
+#if defined(TIOCEXCL) && defined(TIOCNXCL)
+ (void)ioctl(fd, TIOCNXCL, NULL);
+#endif
+ return close(fd);
+}
+
 /*
  *  Tty mode handling
  */
diff --git a/src/tty.h b/src/tty.h
index 1d096ee..d0eee3a 100644
--- a/src/tty.h
+++ b/src/tty.h
@@ -4,6 +4,7 @@
 #include "screen.h"
 
 int   OpenTTY (char *, char *);
+int   CloseTTY (int);
 void  InitTTY (struct mode *, int);
 void  GetTTY (int, struct mode *);
 void  SetTTY (int, struct mode *);
diff --git a/src/window.c b/src/window.c
index 213e090..6499595 100644
--- a/src/window.c
+++ b/src/window.c
@@ -798,15 +798,23 @@ int RemakeWindow(Window *window)
 
 void CloseDevice(Window *window)
 {
-	if (window->w_ptyfd < 0)
+	if (window->w_ptyfd < 0) {
 		return;
-	if (window->w_type == W_TYPE_PTY) {
+  }
+  switch (window->w_type) {
+  case W_TYPE_PTY:
 		/* pty 4 SALE */
 		(void)chmod(window->w_tty, 0666);
 		(void)chown(window->w_tty, 0, 0);
 		ClosePTY(window->w_ptyfd);
-	} else
+    break;
+  case W_TYPE_PLAIN:
+    CloseTTY(window->w_ptyfd);
+    break;
+  default:
 		close(window->w_ptyfd);
+    break;
+  }
 	window->w_ptyfd = -1;
 	window->w_tty[0] = 0;
 	evdeq(&window->w_readev);