[7.1.0] [credentialhelper] Support paths relative to %install_base% (…

…#21532)

This allows us to ship built-in credential helpers (e.g., for `.netrc`)
and move them out of Bazel core.

Closes #21419.

Commit
ed5d444

PiperOrigin-RevId: 611551189
Change-Id: I89c036ef87d4a1eac11c2eff5076e7884d274bb9

Co-authored-by: Yannic Bonenberger <contact@yannic-bonenberger.com>
Co-authored-by: Yun Peng <pcloudy@google.com>

src/main/java/com/google/devtools/build/lib/runtime/CommandLinePathFactory.java

@@ -66,11 +66,16 @@ static CommandLinePathFactory create(FileSystem fileSystem, BlazeDirectories dir
  ImmutableMap.Builder<String, Path> wellKnownRoots = ImmutableMap.builder();
 
  // This is necessary because some tests don't have a workspace set.
- Path workspace = directories.getWorkspace();
+ var workspace = directories.getWorkspace();
  if (workspace != null) {
  wellKnownRoots.put("workspace", workspace);
  }
 
+ var installBase = directories.getInstallBase();
+ if (installBase != null) {
+ wellKnownRoots.put("install_base", installBase);
+ }
+
  return new CommandLinePathFactory(fileSystem, wellKnownRoots.buildOrThrow());
  }