Fix IllegalStateException when reloading several time the same extension

Fixes #1469.

--
Change-Id: I3ffc18208ba346e03658ebeb4d2bb5938113a476
Reviewed-on: https://bazel-review.googlesource.com/6615
MOS_MIGRATED_REVID=136073702

1 files changed, 4 insertions, 5 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/packages/WorkspaceFactory.java b/src/main/java/com/google/devtools/build/lib/packages/WorkspaceFactory.java
index 12c5caa66b..ba1440f2c4 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/WorkspaceFactory.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/WorkspaceFactory.java
@@ -49,6 +49,7 @@ import com.google.devtools.build.lib.syntax.SkylarkList;
 import com.google.devtools.build.lib.syntax.SkylarkSignatureProcessor;
 import com.google.devtools.build.lib.vfs.Path;
 import java.io.File;
+import java.util.HashMap;
 import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -181,11 +182,9 @@ public class WorkspaceFactory {
         .setGlobals(Environment.BUILD)
         .setEventHandler(localReporter);
     if (importedExtensions != null) {
-      importMap =
-          ImmutableMap.<String, Extension>builder()
-              .putAll(parentImportMap)
-              .putAll(importedExtensions)
-              .build();
+      Map<String, Extension> map = new HashMap<String, Extension>(parentImportMap);
+      map.putAll(importedExtensions);
+      importMap = ImmutableMap.<String, Extension>copyOf(importedExtensions);
     } else {
       importMap = parentImportMap;
     }