Serialize workspaceName. -- MOS_MIGRATED_REVID=103547846

diff --git a/src/main/java/com/google/devtools/build/lib/packages/Package.java b/src/main/java/com/google/devtools/build/lib/packages/Package.java
index 39a3de5..b3f75d9 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/Package.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/Package.java

@@ -910,7 +910,8 @@
     /**
      * Uses the workspace name from {@code //external} to set this package's workspace name.
      */
-    Builder setWorkspaceName(String workspaceName) {
+    @VisibleForTesting
+    public Builder setWorkspaceName(String workspaceName) {
       pkg.workspaceName = workspaceName;
       return this;
     }

diff --git a/src/main/java/com/google/devtools/build/lib/packages/PackageDeserializer.java b/src/main/java/com/google/devtools/build/lib/packages/PackageDeserializer.java
index 1a75179..92a97e5 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/PackageDeserializer.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/PackageDeserializer.java

@@ -388,6 +388,8 @@
       builder.setContainsErrors();
     }
 
+    builder.setWorkspaceName(packagePb.getWorkspaceName());
+
     deserializeTargets(in, context);
   }
 

diff --git a/src/main/java/com/google/devtools/build/lib/packages/PackageSerializer.java b/src/main/java/com/google/devtools/build/lib/packages/PackageSerializer.java
index 21c5612..cfc90d5 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/PackageSerializer.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/PackageSerializer.java

@@ -166,6 +166,8 @@
 
     builder.setContainsErrors(pkg.containsErrors());
 
+    builder.setWorkspaceName(pkg.getWorkspaceName());
+
     builder.build().writeDelimitedTo(out);
 
     // Targets are emitted separately as individual protocol buffers as to prevent overwhelming