[gnome-session/revert-db1a97c2] Revert "gnome-session: don't validate shell before using it"

[Ray Strode <halfline src gnome org>]

commit 4415fa832390490df1fcb70a3f756255ce449557
Author: Ray Strode <halfline gmail com>
Date:   Tue Feb 15 20:00:10 2022 +0000

    Revert "gnome-session: don't validate shell before using it"
    
    This reverts commit db1a97c2ffa091a37087cad15c759554e6fbb4ad

 gnome-session/gnome-session.in | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/gnome-session/gnome-session.in b/gnome-session/gnome-session.in
index b4b1f8fa..ddd1a591 100755
--- a/gnome-session/gnome-session.in
+++ b/gnome-session/gnome-session.in
@@ -2,7 +2,10 @@
 
 if [ "x$XDG_SESSION_TYPE" = "xwayland" ] &&
    [ "x$XDG_SESSION_CLASS" != "xgreeter" ] &&
-   [  -n "$SHELL" ]; then
+   [  -n "$SHELL" ] &&
+   grep -q "$SHELL" /etc/shells &&
+   ! (echo "$SHELL" | grep -q "false") &&
+   ! (echo "$SHELL" | grep -q "nologin"); then
   if [ "$1" != '-l' ]; then
     exec bash -c "exec -l '$SHELL' -c '$0 -l $*'"
   else