list-objects: drop process_gitlink() function

Our object graph traversal code has a process_gitlink() function which
we call when we see a gitlink entry. The function does nothing; it was
added in the early days of gitlinks by 6e2f441 (Teach git
list-objects logic to not follow gitlinks, 2007-04-13).

The comment above the function talks about some things we _could_ do.
But in the intervening 15 years, nobody has touched the function, and
the submodule code usually makes its own decisions about when and how to
examine the links. At the generic traversal layer, we can't assume that
the pointed-to commit is available.

Let's drop this placeholder that isn't really helping anything. This
silences some -Wunused-parameter warnings, and also gets rid of a crufty
use of "const unsigned char *" to pass a raw hash value.

Signed-off-by: Jeff King <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: peff

list-objects.c

@@ -81,36 +81,6 @@ static void process_blob(struct traversal_context *ctx,
 	strbuf_setlen(path, pathlen);
 }
 
-/*
- * Processing a gitlink entry currently does nothing, since
- * we do not recurse into the subproject.
- *
- * We *could* eventually add a flag that actually does that,
- * which would involve:
- *  - is the subproject actually checked out?
- *  - if so, see if the subproject has already been added
- *    to the alternates list, and add it if not.
- *  - process the commit (or tag) the gitlink points to
- *    recursively.
- *
- * However, it's unclear whether there is really ever any
- * reason to see superprojects and subprojects as such a
- * "unified" object pool (potentially resulting in a totally
- * humongous pack - avoiding which was the whole point of
- * having gitlinks in the first place!).
- *
- * So for now, there is just a note that we *could* follow
- * the link, and how to do it. Whether it necessarily makes
- * any sense what-so-ever to ever do that is another issue.
- */
-static void process_gitlink(struct traversal_context *ctx,
-			    const unsigned char *sha1,
-			    struct strbuf *path,
-			    const char *name)
-{
-	/* Nothing to do */
-}
-
 static void process_tree(struct traversal_context *ctx,
 			 struct tree *tree,
 			 struct strbuf *base,
@@ -149,8 +119,7 @@ static void process_tree_contents(struct traversal_context *ctx,
 			process_tree(ctx, t, base, entry.path);
 		}
 		else if (S_ISGITLINK(entry.mode))
-			process_gitlink(ctx, entry.oid.hash,
-					base, entry.path);
+			; /* ignore gitlink */
 		else {
 			struct blob *b = lookup_blob(ctx->revs->repo, &entry.oid);
 			if (!b) {