Fix T53812: FBX import fails with long custom property names.

This file also has insanely long object names etc. So added a generic
way to handle names for Blender data (IDs, but also non-ID data like
customprops names, UVLayers, etc.), by truncating names and adding seven
digits from their sha1 hash to their end.

Not sure how much an issue name collisions would be here, but in doubt
that should not hurt.

Too complex/risky of a change to add that one to 2.79a, though.

1 files changed, 18 insertions, 5 deletions

diff --git a/io_scene_fbx/import_fbx.py b/io_scene_fbx/import_fbx.py
index e49d4850..cb67aa76 100644
--- a/io_scene_fbx/import_fbx.py
+++ b/io_scene_fbx/import_fbx.py
@@ -64,6 +64,18 @@ MAT_CONVERT_LAMP = fbx_utils.MAT_CONVERT_LAMP.inverted()
 MAT_CONVERT_CAMERA = fbx_utils.MAT_CONVERT_CAMERA.inverted()
 
 
+def validate_blend_names(name):
+    assert(type(name) == bytes)
+    # Blender typically does not accept names over 63 bytes...
+    if len(name) > 63:
+        import hashlib
+        h = hashlib.sha1(name).hexdigest()
+        return name[:55].decode('utf-8', 'replace') + "_" + h[:7]
+    else:
+        # We use 'replace' even though FBX 'specs' say it should always be utf8, see T53841.
+        return name.decode('utf-8', 'replace')
+
+
 def elem_find_first(elem, id_search, default=None):
     for fbx_item in elem.elems:
         if fbx_item.id == id_search:
@@ -124,14 +136,14 @@ def elem_name_ensure_class(elem, clss=...):
     elem_name, elem_class = elem_split_name_class(elem)
     if clss is not ...:
         assert(elem_class == clss)
-    return elem_name.decode('utf-8', 'replace')
+    return validate_blend_names(elem_name)
 
 
 def elem_name_ensure_classes(elem, clss=...):
     elem_name, elem_class = elem_split_name_class(elem)
     if clss is not ...:
         assert(elem_class in clss)
-    return elem_name.decode('utf-8', 'replace')
+    return validate_blend_names(elem_name)
 
 
 def elem_split_name_class_nodeattr(elem):
@@ -312,9 +324,10 @@ def blen_read_custom_properties(fbx_obj, blen_obj, settings):
                     for item in items.split('\r\n'):
                         if item:
                             prop_name, prop_value = item.split('=', 1)
-                            blen_obj[prop_name.strip()] = prop_value.strip()
+                            prop_name = validate_blend_names(prop_name.strip().encode('utf-8'))
+                            blen_obj[prop_name] = prop_value.strip()
                 else:
-                    prop_name = fbx_prop.props[0].decode('utf-8', 'replace')
+                    prop_name = validate_blend_names(fbx_prop.props[0])
                     prop_type = fbx_prop.props[1]
                     if prop_type in {b'Vector', b'Vector3D', b'Color', b'ColorRGB'}:
                         assert(fbx_prop.props_type[4:7] == bytes((data_types.FLOAT64,)) * 3)
@@ -715,7 +728,7 @@ def blen_read_animations(fbx_tmpl_astack, fbx_tmpl_alayer, stacks, scene, anim_o
 
 def blen_read_geom_layerinfo(fbx_layer):
     return (
-        elem_find_first_string(fbx_layer, b'Name'),
+        validate_blend_names(elem_find_first_string_as_bytes(fbx_layer, b'Name')),
         elem_find_first_string_as_bytes(fbx_layer, b'MappingInformationType'),
         elem_find_first_string_as_bytes(fbx_layer, b'ReferenceInformationType'),
         )