fix proto regression

WORKSPACE

@@ -51,6 +51,11 @@ load("//scala:scala_cross_version.bzl", "default_scala_major_version", "scala_mv
 
 MAVEN_SERVER_URLS = default_maven_server_urls()
 
+# needed for the cross repo proto test
+load("//test/proto_cross_repo_boundary:repo.bzl", "proto_cross_repo_boundary_repository")
+
+proto_cross_repo_boundary_repository()
+
 # test adding a scala jar:
 jvm_maven_import_external(
     name = "com_twitter__scalding_date",

scala/private/resources.bzl

@@ -21,7 +21,8 @@ def _target_path_by_strip_prefix(resource, resource_strip_prefix):
     # Start from absolute resource path and then strip roots so we get to correct short path
     # resource.short_path sometimes give weird results ie '../' prefix
     path = resource.path
-    path = _strip_prefix(path, resource.owner.workspace_root + "/")
+    if resource_strip_prefix != resource.owner.workspace_root:
+        path = _strip_prefix(path, resource.owner.workspace_root + "/")
     path = _strip_prefix(path, resource.root.path + "/")
 
     # proto_library translates strip_import_prefix to proto_source_root which includes root so we have to strip it

test/proto_cross_repo_boundary/BUILD

@@ -0,0 +1,7 @@
+load("@io_bazel_rules_scala//scala_proto:scala_proto.bzl", "scalapb_proto_library")
+
+scalapb_proto_library(
+    name = "sample_scala_proto",
+    visibility = ["//visibility:public"],
+    deps = ["@proto_cross_repo_boundary//:sample_proto"],
+)

test/proto_cross_repo_boundary/repo.bzl

@@ -0,0 +1,6 @@
+def proto_cross_repo_boundary_repository():
+    native.new_local_repository(
+        name = "proto_cross_repo_boundary",
+        path = "test/proto_cross_repo_boundary/repo",
+        build_file = "test/proto_cross_repo_boundary/repo/BUILD.repo",
+    )

test/proto_cross_repo_boundary/repo/BUILD.repo

@@ -0,0 +1,5 @@
+proto_library(
+    name = "sample_proto",
+    srcs = ["sample.proto"],
+    visibility = ["//visibility:public"],
+)

test/proto_cross_repo_boundary/repo/sample.proto

@@ -0,0 +1,9 @@
+syntax = "proto3";
+
+package sample;
+
+option java_package = "sample";
+
+message Sample {
+  repeated string foobar = 1;
+}