From 3ece54fb9446d7c8ed2a796ebf26bfedae58f15c Mon Sep 17 00:00:00 2001
From: rlar <rlar>
Date: Thu, 2 Jun 2011 19:34:47 +0000
Subject: [PATCH] bug fix, avoid segfault when indexing a vector with a
 nonexistant variable

---
 ChangeLog              |  5 +++++
 src/frontend/com_let.c | 12 +++++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 9c56c82e8..b27806f9d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2011-06-02  Robert Larice
+ * src/frontend/com_let.c :
+   bug fix, avoid segfault when indexing a vector with a nonexistant variable
+     let foo = thing[nonsuchthing]
+
 2011-06-02  Robert Larice
  * src/frontend/postcoms.c :
    bug fix, avoid $curplot (plot_names) being assembled from negative numbers
diff --git a/src/frontend/com_let.c b/src/frontend/com_let.c
index bd41a127d..b3fb2b141 100644
--- a/src/frontend/com_let.c
+++ b/src/frontend/com_let.c
@@ -79,8 +79,18 @@ com_let(wordlist *wl)
 	    /* va, indexing */
 	    fake_wl.wl_word = s;
 	    nn = ft_getpnames(&fake_wl, TRUE);
+	    if (!nn) {
+		/* XXX error message */
+		tfree(p);
+		return;
+	    }
 	    t = ft_evaluate(nn);
-
+	    if (!t) {
+		fprintf(cp_err, "Error: Can't evaluate %s\n", s);
+		free_pnode(nn);
+		tfree(p);
+		return;
+	    }
 	    if (!isreal(t) || t->v_link2 || t->v_length != 1 || !t->v_realdata)
 	    {
 		fprintf(cp_err, "Error: index is not a scalar.\n");