From 5edaa3a81618b24ecf2b7ecfad486a39fe778c98 Mon Sep 17 00:00:00 2001
From: Graeme Campbell <graeme.campbell@alliedtelesis.co.nz>
Date: Mon, 19 Aug 2024 16:20:59 +1200
Subject: [PATCH] Fix crash with queries to proxy-node schemas

Querying the fields of a model with a proxy node, with the option of
report-all causes a crash in apteryx-xml/schema.c in the function
_sch_traverse_nodes. This is due to schema being set to NULL while
handling the proxy node. This change exits the routine early if schema
is set to NULL.
---
 schema.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/schema.c b/schema.c
index 2a19f1a..1adf8ae 100644
--- a/schema.c
+++ b/schema.c
@@ -3149,6 +3149,12 @@ _sch_traverse_nodes (sch_instance * instance, sch_node * schema, GNode * parent,
             g_free (name);
             name = sch_name (schema);
         }
+        else
+        {
+            /* This can happen if a query is for a field of the proxy schema itself */
+            rc = false;
+            goto exit;
+        }
         depth++;
     }