From 5f966934df111994e58b9e5cae86133e525329df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sybren=20A=2E=20St=C3=BCvel?= <sybren@stuvel.eu>
Date: Thu, 7 Jun 2018 15:18:18 +0200
Subject: [PATCH] Blender 2.8 fixes because of removed Material.mtex and
 Material.group

---
 blender_asset_tracer/blendfile/dna.py   |  3 +++
 blender_asset_tracer/trace/expanders.py | 10 +++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/blender_asset_tracer/blendfile/dna.py b/blender_asset_tracer/blendfile/dna.py
index 8ebbb52..ce40194 100644
--- a/blender_asset_tracer/blendfile/dna.py
+++ b/blender_asset_tracer/blendfile/dna.py
@@ -148,6 +148,9 @@ class Struct:
         """
         return self._fields
 
+    def has_field(self, field_name: bytes) -> bool:
+        return field_name in self._fields_by_name
+
     def field_from_path(self,
                         pointer_size: int,
                         path: FieldPath) \
diff --git a/blender_asset_tracer/trace/expanders.py b/blender_asset_tracer/trace/expanders.py
index 21d5469..540be0f 100644
--- a/blender_asset_tracer/trace/expanders.py
+++ b/blender_asset_tracer/trace/expanders.py
@@ -70,6 +70,10 @@ def _expand_generic_material(block: blendfile.BlendFileBlock):
 
 
 def _expand_generic_mtex(block: blendfile.BlendFileBlock):
+    if not block.dna_type.has_field(b'mtex'):
+        # mtex was removed in Blender 2.8
+        return
+
     for mtex in block.iter_fixed_array_of_pointers(b'mtex'):
         yield mtex.get_pointer(b'tex')
         yield mtex.get_pointer(b'object')
@@ -137,7 +141,11 @@ def _expand_material(block: blendfile.BlendFileBlock):
     yield from _expand_generic_nodetree_id(block)
     yield from _expand_generic_mtex(block)
 
-    yield block.get_pointer(b'group')
+    try:
+        yield block.get_pointer(b'group')
+    except KeyError:
+        # Groups were removed from Blender 2.8
+        pass
 
 
 @dna_code('MB')