Fixing issue with external j2objc protos

The output files are created without a repository, but the expected
filenames have them

This resolves issues when having a proto_library from an external build
file.

This seems to be a regression, so maybe should go into the 0.8.0 branch?

Note: Work at Square and we have a signed CLA with google

Note, without this fix we get errors like

```
ERROR: /private/var/tmp/_bazel_lewis/4a25cfc2b9b758043413ac58525ef6b4/external/AllProtos/BUILD.bazel:27:1: output 'external/AllProtos/squareup/objc/objc.j2objc.pb.m' was not created
ERROR: /private/var/tmp/_bazel_lewis/4a25cfc2b9b758043413ac58525ef6b4/external/AllProtos/BUILD.bazel:27:1: output 'external/AllProtos/squareup/objc/objc.j2objc.pb.h' was not created
```

Closes #4058.

PiperOrigin-RevId: 187480864

1 files changed, 6 insertions, 17 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/proto/ProtoCompileActionBuilder.java b/src/main/java/com/google/devtools/build/lib/rules/proto/ProtoCompileActionBuilder.java
index 6fdcc040f0..c0767acdf0 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/proto/ProtoCompileActionBuilder.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/proto/ProtoCompileActionBuilder.java
@@ -611,26 +611,15 @@ public class ProtoCompileActionBuilder {
   }
 
   private static void expandTransitiveImportArg(Artifact artifact, Consumer<String> args) {
-    args.accept("-I" + getPathIgnoringRepository(artifact) + "=" + artifact.getExecPathString());
+    args.accept(
+        "-I"
+            + ProtoCommon.getPathIgnoringRepository(artifact).toString()
+            + "="
+            + artifact.getExecPathString());
   }
 
   private static void expandToPathIgnoringRepository(Artifact artifact, Consumer<String> args) {
-    args.accept(getPathIgnoringRepository(artifact));
-  }
-
-  /**
-   * Gets the artifact's path relative to the root, ignoring the external repository the artifact is
-   * at. For example, <code>
-   * //a:b.proto --> a/b.proto
-   * {@literal @}foo//a:b.proto --> a/b.proto
-   * </code>
-   */
-  private static String getPathIgnoringRepository(Artifact artifact) {
-    return artifact
-        .getRootRelativePath()
-        .relativeTo(
-            artifact.getOwnerLabel().getPackageIdentifier().getRepository().getPathUnderExecRoot())
-        .toString();
+    args.accept(ProtoCommon.getPathIgnoringRepository(artifact).toString());
   }
 
   /**