Check for presence of SHELL environment variable

- POSIX states the SHELL environment variable "... shall represent a
  pathname of the user's preferred command language interpreter." As
  such, st should check for its presence when deciding what shell to
  use; just as HOME can be defined to override one's passwd-defined home
  directory, a user should also be able to override their passwd-defined
  shell using the SHELL environment variable.

1 files changed, 4 insertions, 1 deletions

diff --git a/st.c b/st.c
index ad52280..068fbb3 100644
--- a/st.c
+++ b/st.c
@@ -1158,7 +1158,10 @@ execsh(void) {
                         die("who are you?\n");
         }
 
-        sh = (pw->pw_shell[0]) ? pw->pw_shell : shell;
+        if (!(sh = getenv("SHELL"))) {
+                sh = (pw->pw_shell[0]) ? pw->pw_shell : shell;
+        }
+
         if(opt_cmd)
                 prog = opt_cmd[0];
         else if(utmp)