From d3fcf2f43f60be7a8ac4589339c049b63eb216d2 Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Sun, 22 Mar 2020 11:59:28 +0100
Subject: [PATCH] restrict removal of arg only to comma operator, otherwise
 functions with a single variable may fail

---
 src/frontend/parse.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/frontend/parse.c b/src/frontend/parse.c
index 2c6e9d0ff..a41d61202 100644
--- a/src/frontend/parse.c
+++ b/src/frontend/parse.c
@@ -307,7 +307,10 @@ struct pnode *PP_mkfnode(const char *func, struct pnode *arg)
         /* Give the user-defined functions a try. */
         q = ft_substdef(func, arg);
         if (q) { /* found */
-            free_pnode(arg);
+            /* remove only the old comma operator pnode, no longer used */
+            if (arg->pn_op && arg->pn_op->op_num == PT_OP_COMMA) {
+                free_pnode(arg);
+            }
             return q;
         }
     }