Fix a bug in which Bazel reports action conflicts between ActionTemplates and associated expanded actions.

--
MOS_MIGRATED_REVID=136212908

1 files changed, 13 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/actions/Actions.java b/src/main/java/com/google/devtools/build/lib/actions/Actions.java
index 44397d8e97..b8bd981156 100644
--- a/src/main/java/com/google/devtools/build/lib/actions/Actions.java
+++ b/src/main/java/com/google/devtools/build/lib/actions/Actions.java
@@ -190,6 +190,19 @@ public final class Actions {
         if (pathJ.startsWith(pathI)) { // prefix conflict.
           Artifact artifactI = Preconditions.checkNotNull(artifactPathMap.get(pathI), pathI);
           Artifact artifactJ = Preconditions.checkNotNull(artifactPathMap.get(pathJ), pathJ);
+
+          // We ignore the artifact prefix conflict between a TreeFileArtifact and its parent
+          // TreeArtifact.
+          // We can only have such a conflict here if:
+          // 1. The TreeArtifact is generated by an ActionTemplate. And the TreeFileArtifact is
+          //    generated by an expanded action created at execution time from the ActionTemplate.
+          // 2. This is an incremental build with invalidated configured targets. In this case,
+          //    the action graph contains expanded actions from previous builds and they will be
+          //    checked for artifact conflicts.
+          if (artifactJ.hasParent() && artifactJ.getParent().equals(artifactI)) {
+            continue;
+          }
+
           ActionAnalysisMetadata actionI =
               Preconditions.checkNotNull(actionGraph.getGeneratingAction(artifactI), artifactI);
           ActionAnalysisMetadata actionJ =