From f4472f788e6c330436a9d8619de83e95ee379165 Mon Sep 17 00:00:00 2001
From: rlar <rlar>
Date: Mon, 4 May 2015 20:17:28 +0200
Subject: [PATCH] spicelib/parser/inpptree.c, bug fix, "#287 Shared library
 crashes on using non existing functions "

"remcirc" has the potential to invoke INPfreeTree() with a NULL IFparseTree

Thanks to Craggan, who reported this in:
  http://sourceforge.net/p/ngspice/bugs/287/
---
 src/spicelib/parser/inpptree.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/spicelib/parser/inpptree.c b/src/spicelib/parser/inpptree.c
index 0dac42703..956b190cc 100644
--- a/src/spicelib/parser/inpptree.c
+++ b/src/spicelib/parser/inpptree.c
@@ -1409,6 +1409,9 @@ void INPfreeTree(IFparseTree *ptree)
 
     int i;
 
+    if (!pt)
+        return;
+
     for (i = 0; i < pt->p.numVars; i++)
         dec_usage(pt->derivs[i]);