Fix ValueBlock Relationship was not handled correctly.

Author: syoyo

src/ascii-parser.cc

@@ -3519,6 +3519,7 @@ bool AsciiParser::ParseRelationship(Relationship *result) {
       PUSH_ERROR_AND_RETURN("Failed to parse None.");
     }
 
+    DCOUT("Relationship valueblock.");
     result->set_blocked();
   } else {
     PUSH_ERROR_AND_RETURN("Unexpected char \"" + std::to_string(c) +
@@ -3804,7 +3805,8 @@ bool AsciiParser::ParsePrimProps(std::map<std::string, Property> *props,
       PUSH_ERROR_AND_RETURN("Failed to parse `rel` property.");
     }
 
-    if (!SkipWhitespace()) {
+    if (!SkipCommentAndWhitespaceAndNewline()) {
+      return false;
     }
 
     if (!LookChar1(&c)) {

src/prim-reconstruct.cc

@@ -1399,8 +1399,12 @@ static ParseResult ParseShaderInputConnectionProperty(std::set<std::string> &tab
       __target = rel; \
       table.insert(prop.first); \
       DCOUT("Added rel " << __propname); \
+    } else if (rel.is_blocked()) { \
+      __target = rel; \
+      table.insert(prop.first); \
+      DCOUT("Added ValueBlocked rel " << __propname); \
     } else { \
-      PUSH_ERROR_AND_RETURN(fmt::format("`{}` target must be Path.", __propname)); \
+      PUSH_ERROR_AND_RETURN(fmt::format("Internal error. Property `{}` is not a valid Relationship.", __propname)); \
     } \
   }
 

tests/usda/material-binding-none-001.usda

@@ -0,0 +1,8 @@
+#usda 1.0
+
+def Xform "geom"
+{
+  # common material
+  rel material:binding = None
+
+}

tests/usda/material-binding-none-002.usda

@@ -0,0 +1,6 @@
+#usda 1.0
+
+def Xform "geom"
+{
+  rel material:binding = None ( bindMaterialAs = "strongerThanDescendants" )
+}