Canonicalize worktree path in BaseRepositoryBuilder if set via config

This is the case for submodules in .git/modules, which typically have a
worktree config of "../../../dir". This can confuse callers, which e.g.
try to call Repository.stripWorkDir with it.

Bug: 423644
Change-Id: I0c00953f73f9316a66d0fc10eab52d8779c88f00
Signed-off-by: Robin Stocker <robin@nibor.org>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit/src/org/eclipse/jgit/lib/BaseRepositoryBuilder.java

@@ -695,7 +695,7 @@ public class BaseRepositoryBuilder<B extends BaseRepositoryBuilder, R extends Re
 		String path = cfg.getString(CONFIG_CORE_SECTION, null,
 				CONFIG_KEY_WORKTREE);
 		if (path != null)
-			return safeFS().resolve(getGitDir(), path);
+			return safeFS().resolve(getGitDir(), path).getCanonicalFile();
 
 		// If core.bare is set, honor its value. Assume workTree is
 		// the parent directory of the repository.