Support proto libraries with no headers, whenever that happens. (ihavenoideawhatimdoing.jpg)

PiperOrigin-RevId: 473967082
diff --git a/rs_bindings_from_cc/bazel_support/rust_bindings_from_cc_aspect.bzl b/rs_bindings_from_cc/bazel_support/rust_bindings_from_cc_aspect.bzl
index 253e8b7..9dd1f58 100644
--- a/rs_bindings_from_cc/bazel_support/rust_bindings_from_cc_aspect.bzl
+++ b/rs_bindings_from_cc/bazel_support/rust_bindings_from_cc_aspect.bzl
@@ -106,8 +106,8 @@
     elif _is_proto_library(target):
         #TODO(b/232199093): Ideally we would get this information from a proto-specific provider,
         # but ProtoCcFilesProvider is private currently. Use it once public.
-        proto_header = target[CcInfo].compilation_context.direct_headers[0]
-        public_hdrs = [proto_header]
+        # (Slicing because e.g. portable_proto_library has an empty direct_headers.)
+        public_hdrs = target[CcInfo].compilation_context.direct_headers[0:1]
         all_standalone_hdrs = public_hdrs
         extra_rule_specific_deps = [ctx.rule.attr._cc_lib]
     elif ctx.rule.kind == "cc_embed_data":