From b1f4f32b363085b1cf0a3ab278a695aa99b5ddba Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Mon, 18 Aug 2025 23:49:53 +0200
Subject: [PATCH] Prevent a segfault if cp_variablesubst return a nullptr.
 Fixes bug-801

---
 src/frontend/control.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/frontend/control.c b/src/frontend/control.c
index 5c724ec12..9c982ef23 100644
--- a/src/frontend/control.c
+++ b/src/frontend/control.c
@@ -147,6 +147,10 @@ docommand(wordlist *wlist)
     /* Do all the things that used to be done by cshpar when the line
      * was read...  */
     wlist = cp_variablesubst(wlist);
+
+    if (!wlist || !wlist->wl_word)
+        return;
+
     pwlist(wlist, "After variable substitution");
 
     wlist = cp_bquote(wlist);