dispatch-conf: ignore SHELL in spawn_shell

There is no need to use SHELL here, and this can actually cause problems
when SHELL is set to "nologin" or "false".

Look for sh in PATH instead.

Bug: https://bugs.gentoo.org/910560
Signed-off-by: Mike Gilbert <floppym@gentoo.org>

1 files changed, 11 insertions, 19 deletions

diff --git a/bin/dispatch-conf b/bin/dispatch-conf
index 93164d909..2e7256243 100755
--- a/bin/dispatch-conf
+++ b/bin/dispatch-conf
@@ -574,26 +574,18 @@ def clear_screen():
     os.system("clear 2>/dev/null")
 
 
-shell = os.environ.get("SHELL")
-if not shell or not os.access(shell, os.EX_OK):
-    shell = find_binary("sh")
-
-
 def spawn_shell(cmd):
-    if shell:
-        sys.__stdout__.flush()
-        sys.__stderr__.flush()
-        spawn(
-            [shell, "-c", cmd],
-            env=os.environ,
-            fd_pipes={
-                0: portage._get_stdin().fileno(),
-                1: sys.__stdout__.fileno(),
-                2: sys.__stderr__.fileno(),
-            },
-        )
-    else:
-        os.system(cmd)
+    sys.__stdout__.flush()
+    sys.__stderr__.flush()
+    spawn(
+        ["sh", "-c", cmd],
+        env=os.environ,
+        fd_pipes={
+            0: portage._get_stdin().fileno(),
+            1: sys.__stdout__.fileno(),
+            2: sys.__stderr__.fileno(),
+        },
+    )
 
 
 def usage(argv):