ref-filter: properly distinuish pseudo and root refs

The ref-filter interfaces currently define root refs as either a
detached HEAD or a pseudo ref. Pseudo refs aren't root refs though, so
let's properly distinguish those ref types.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/for-each-ref.c

@@ -98,7 +98,7 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
 	}
 
 	if (include_root_refs)
-		flags |= FILTER_REFS_ROOT_REFS;
+		flags |= FILTER_REFS_ROOT_REFS | FILTER_REFS_DETACHED_HEAD;
 
 	filter.match_as_path = 1;
 	filter_and_format_refs(&filter, flags, sorting, &format);

ref-filter.c

@@ -2628,7 +2628,7 @@ static int for_each_fullref_in_pattern(struct ref_filter *filter,
 				       each_ref_fn cb,
 				       void *cb_data)
 {
-	if (filter->kind == FILTER_REFS_KIND_MASK) {
+	if (filter->kind & FILTER_REFS_ROOT_REFS) {
 		/* In this case, we want to print all refs including root refs. */
 		return refs_for_each_include_root_refs(get_main_ref_store(the_repository),
 						       cb, cb_data);
@@ -2756,8 +2756,10 @@ static int ref_kind_from_refname(const char *refname)
 			return ref_kind[i].kind;
 	}
 
-	if (is_root_ref(refname))
+	if (is_pseudo_ref(refname))
 		return FILTER_REFS_PSEUDOREFS;
+	if (is_root_ref(refname))
+		return FILTER_REFS_ROOT_REFS;
 
 	return FILTER_REFS_OTHERS;
 }
@@ -2794,11 +2796,11 @@ static struct ref_array_item *apply_ref_filter(const char *refname, const struct
 	/*
 	 * Generally HEAD refs are printed with special description denoting a rebase,
 	 * detached state and so forth. This is useful when only printing the HEAD ref
-	 * But when it is being printed along with other pseudorefs, it makes sense to
+	 * But when it is being printed along with other root refs, it makes sense to
-	 * keep the formatting consistent. So we mask the type to act like a pseudoref.
+	 * keep the formatting consistent. So we mask the type to act like a root ref.
 	 */
-	if (filter->kind == FILTER_REFS_KIND_MASK && kind == FILTER_REFS_DETACHED_HEAD)
+	if (filter->kind & FILTER_REFS_ROOT_REFS && kind == FILTER_REFS_DETACHED_HEAD)
-		kind = FILTER_REFS_PSEUDOREFS;
+		kind = FILTER_REFS_ROOT_REFS;
 	else if (!(kind & filter->kind))
 		return NULL;
 
@@ -3072,7 +3074,7 @@ static int do_filter_refs(struct ref_filter *filter, unsigned int type, each_ref
 		 * When printing all ref types, HEAD is already included,
 		 * so we don't want to print HEAD again.
 		 */
-		if (!ret && (filter->kind != FILTER_REFS_KIND_MASK) &&
+		if (!ret && !(filter->kind & FILTER_REFS_ROOT_REFS) &&
 		    (filter->kind & FILTER_REFS_DETACHED_HEAD))
 			head_ref(fn, cb_data);
 	}

ref-filter.h

@@ -23,9 +23,9 @@
 				    FILTER_REFS_REMOTES | FILTER_REFS_OTHERS)
 #define FILTER_REFS_DETACHED_HEAD  0x0020
 #define FILTER_REFS_PSEUDOREFS     0x0040
-#define FILTER_REFS_ROOT_REFS      (FILTER_REFS_DETACHED_HEAD | FILTER_REFS_PSEUDOREFS)
+#define FILTER_REFS_ROOT_REFS      0x0080
 #define FILTER_REFS_KIND_MASK      (FILTER_REFS_REGULAR | FILTER_REFS_DETACHED_HEAD | \
-				    FILTER_REFS_PSEUDOREFS)
+				    FILTER_REFS_PSEUDOREFS | FILTER_REFS_ROOT_REFS)
 
 struct atom_value;
 struct ref_sorting;

refs.c

@@ -844,24 +844,8 @@ int is_per_worktree_ref(const char *refname)
 	       starts_with(refname, "refs/rewritten/");
 }
 
-static int is_pseudo_ref(const char *refname)
+int is_pseudo_ref(const char *refname)
 {
-	/*
-	 * Pseudorefs are refs that have different semantics compared to
-	 * "normal" refs. These refs can thus not be stored in the ref backend,
-	 * but must always be accessed via the filesystem. The following refs
-	 * are pseudorefs:
-	 *
-	 * - FETCH_HEAD may contain multiple object IDs, and each one of them
-	 *   carries additional metadata like where it came from.
-	 *
-	 * - MERGE_HEAD may contain multiple object IDs when merging multiple
-	 *   heads.
-	 *
-	 * Reading, writing or deleting references must consistently go either
-	 * through the filesystem (pseudorefs) or through the reference
-	 * backend (normal ones).
-	 */
 	static const char * const pseudo_refs[] = {
 		"FETCH_HEAD",
 		"MERGE_HEAD",

refs.h

@@ -1080,4 +1080,22 @@ void update_ref_namespace(enum ref_namespace namespace, char *ref);
  */
 int is_root_ref(const char *refname);
 
+/*
+ * Pseudorefs are refs that have different semantics compared to
+ * "normal" refs. These refs can thus not be stored in the ref backend,
+ * but must always be accessed via the filesystem. The following refs
+ * are pseudorefs:
+ *
+ * - FETCH_HEAD may contain multiple object IDs, and each one of them
+ *   carries additional metadata like where it came from.
+ *
+ * - MERGE_HEAD may contain multiple object IDs when merging multiple
+ *   heads.
+ *
+ * Reading, writing or deleting references must consistently go either
+ * through the filesystem (pseudorefs) or through the reference
+ * backend (normal ones).
+ */
+int is_pseudo_ref(const char *refname);
+
 #endif /* REFS_H */