[rtems commit] shell.c: Fix Dereference before null check (CID #1467420)

[Joel Sherrill]

Module:    rtems
Branch:    master
Commit:    fa25b73ac191fd9e4664da3197aef874488cee0e
Changeset: http://git.rtems.org/rtems/commit/?id=fa25b73ac191fd9e4664da3197aef874488cee0e

Author:    Ryan Long <thisisryanlong at gmail.com>
Date:      Thu Feb 18 09:35:13 2021 -0500

shell.c: Fix Dereference before null check (CID #1467420)

CID 1467420: Dereference before null check in rtems_shell_line_editor().

Closes #4254

---

 cpukit/libmisc/shell/shell.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/cpukit/libmisc/shell/shell.c b/cpukit/libmisc/shell/shell.c
index 3c357a1..1e5962b 100644
--- a/cpukit/libmisc/shell/shell.c
+++ b/cpukit/libmisc/shell/shell.c
@@ -320,7 +320,10 @@ static int rtems_shell_line_editor(
   int          cmd = -1;
   int          inserting = 1;
   int          in_fileno = fileno(in);
-  int          out_fileno = fileno(out);
+  int          out_fileno;
+
+  _Assert(out != NULL);
+  out_fileno = fileno(out);
 
   /*
    * Only this task can use this file descriptor because calling