C++ libraries in remote repos don't need to set include paths

Fixes #445, based on https://github.com/bazelbuild/bazel/compare/master...ulfjack:cpp-include-path.

RELNOTES: C++ libraries no longer need includes = ["."] (or similar copts) to include paths relative to a remote repository's root.

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MOS_MIGRATED_REVID=107593486

1 files changed, 3 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/vfs/PathFragment.java b/src/main/java/com/google/devtools/build/lib/vfs/PathFragment.java
index 434cdcfc2c..97221abf6f 100644
--- a/src/main/java/com/google/devtools/build/lib/vfs/PathFragment.java
+++ b/src/main/java/com/google/devtools/build/lib/vfs/PathFragment.java
@@ -379,6 +379,9 @@ public final class PathFragment implements Comparable<PathFragment>, Serializabl
    * with no path normalization or I/O performed.
    */
   public PathFragment getRelative(PathFragment otherFragment) {
+    if (otherFragment == EMPTY_FRAGMENT) {
+      return this;
+    }
     return otherFragment.isAbsolute()
         ? otherFragment
         : new PathFragment(this, otherFragment);