1 files changed, 94 insertions, 27 deletions

diff --git a/builtin/describe.c b/builtin/describe.c
index e14e162ef..3b0b204b1 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -3,6 +3,7 @@
 #include "lockfile.h"
 #include "commit.h"
 #include "tag.h"
+#include "blob.h"
 #include "refs.h"
 #include "builtin.h"
 #include "exec_cmd.h"
@@ -12,6 +13,8 @@
 #include "hashmap.h"
 #include "argv-array.h"
 #include "run-command.h"
+#include "revision.h"
+#include "list-objects.h"
 
 #define MAX_TAGS	(FLAG_BITS - 1)
 
@@ -256,7 +259,7 @@ static unsigned long finish_depth_computation(
 	return seen_commits;
 }
 
-static void display_name(struct commit_name *n)
+static void append_name(struct commit_name *n, struct strbuf *dst)
 {
 	if (n->prio == 2 && !n->tag) {
 		n->tag = lookup_tag(&n->oid);
@@ -272,19 +275,18 @@ static void display_name(struct commit_name *n)
 	}
 
 	if (n->tag)
-		printf("%s", n->tag->tag);
+		strbuf_addstr(dst, n->tag->tag);
 	else
-		printf("%s", n->path);
+		strbuf_addstr(dst, n->path);
 }
 
-static void show_suffix(int depth, const struct object_id *oid)
+static void append_suffix(int depth, const struct object_id *oid, struct strbuf *dst)
 {
-	printf("-%d-g%s", depth, find_unique_abbrev(oid->hash, abbrev));
+	strbuf_addf(dst, "-%d-g%s", depth, find_unique_abbrev(oid->hash, abbrev));
 }
 
-static void describe(const char *arg, int last_one)
+static void describe_commit(struct object_id *oid, struct strbuf *dst)
 {
-	struct object_id oid;
 	struct commit *cmit, *gave_up_on = NULL;
 	struct commit_list *list;
 	struct commit_name *n;
@@ -293,30 +295,25 @@ static void describe(const char *arg, int last_one)
 	unsigned long seen_commits = 0;
 	unsigned int unannotated_cnt = 0;
 
-	if (get_oid(arg, &oid))
-		die(_("Not a valid object name %s"), arg);
-	cmit = lookup_commit_reference(&oid);
-	if (!cmit)
-		die(_("%s is not a valid '%s' object"), arg, commit_type);
+	cmit = lookup_commit_reference(oid);
 
 	n = find_commit_name(&cmit->object.oid);
 	if (n && (tags || all || n->prio == 2)) {
 		/*
 		 * Exact match to an existing ref.
 		 */
-		display_name(n);
+		append_name(n, dst);
 		if (longformat)
-			show_suffix(0, n->tag ? &n->tag->tagged->oid : &oid);
+			append_suffix(0, n->tag ? &n->tag->tagged->oid : oid, dst);
 		if (suffix)
-			printf("%s", suffix);
-		printf("\n");
+			strbuf_addstr(dst, suffix);
 		return;
 	}
 
 	if (!max_candidates)
 		die(_("no tag exactly matches '%s'"), oid_to_hex(&cmit->object.oid));
 	if (debug)
-		fprintf(stderr, _("searching to describe %s\n"), arg);
+		fprintf(stderr, _("No exact match on refs or tags, searching to describe\n"));
 
 	if (!have_util) {
 		struct hashmap_iter iter;
@@ -381,22 +378,21 @@ static void describe(const char *arg, int last_one)
 	}
 
 	if (!match_cnt) {
-		struct object_id *oid = &cmit->object.oid;
+		struct object_id *cmit_oid = &cmit->object.oid;
 		if (always) {
-			printf("%s", find_unique_abbrev(oid->hash, abbrev));
+			strbuf_addstr(dst, find_unique_abbrev(cmit_oid->hash, abbrev));
 			if (suffix)
-				printf("%s", suffix);
-			printf("\n");
+				strbuf_addstr(dst, suffix);
 			return;
 		}
 		if (unannotated_cnt)
 			die(_("No annotated tags can describe '%s'.\n"
 			    "However, there were unannotated tags: try --tags."),
-			    oid_to_hex(oid));
+			    oid_to_hex(cmit_oid));
 		else
 			die(_("No tags can describe '%s'.\n"
 			    "Try --always, or create some tags."),
-			    oid_to_hex(oid));
+			    oid_to_hex(cmit_oid));
 	}
 
 	QSORT(all_matches, match_cnt, compare_pt);
@@ -434,15 +430,86 @@ static void describe(const char *arg, int last_one)
 		}
 	}
 
-	display_name(all_matches[0].name);
+	append_name(all_matches[0].name, dst);
 	if (abbrev)
-		show_suffix(all_matches[0].depth, &cmit->object.oid);
+		append_suffix(all_matches[0].depth, &cmit->object.oid, dst);
 	if (suffix)
-		printf("%s", suffix);
-	printf("\n");
+		strbuf_addstr(dst, suffix);
+}
+
+struct process_commit_data {
+	struct object_id current_commit;
+	struct object_id looking_for;
+	struct strbuf *dst;
+	struct rev_info *revs;
+};
+
+static void process_commit(struct commit *commit, void *data)
+{
+	struct process_commit_data *pcd = data;
+	pcd->current_commit = commit->object.oid;
+}
+
+static void process_object(struct object *obj, const char *path, void *data)
+{
+	struct process_commit_data *pcd = data;
+
+	if (!oidcmp(&pcd->looking_for, &obj->oid) && !pcd->dst->len) {
+		reset_revision_walk();
+		describe_commit(&pcd->current_commit, pcd->dst);
+		strbuf_addf(pcd->dst, ":%s", path);
+		free_commit_list(pcd->revs->commits);
+		pcd->revs->commits = NULL;
+	}
+}
+
+static void describe_blob(struct object_id oid, struct strbuf *dst)
+{
+	struct rev_info revs;
+	struct argv_array args = ARGV_ARRAY_INIT;
+	struct process_commit_data pcd = { null_oid, oid, dst, &revs};
+
+	argv_array_pushl(&args, "internal: The first arg is not parsed",
+		"--objects", "--in-commit-order", "--reverse", "HEAD",
+		NULL);
+
+	init_revisions(&revs, NULL);
+	if (setup_revisions(args.argc, args.argv, &revs, NULL) > 1)
+		BUG("setup_revisions could not handle all args?");
+
+	if (prepare_revision_walk(&revs))
+		die("revision walk setup failed");
+
+	traverse_commit_list(&revs, process_commit, process_object, &pcd);
+	reset_revision_walk();
+}
+
+static void describe(const char *arg, int last_one)
+{
+	struct object_id oid;
+	struct commit *cmit;
+	struct strbuf sb = STRBUF_INIT;
+
+	if (debug)
+		fprintf(stderr, _("describe %s\n"), arg);
+
+	if (get_oid(arg, &oid))
+		die(_("Not a valid object name %s"), arg);
+	cmit = lookup_commit_reference_gently(&oid, 1);
+
+	if (cmit)
+		describe_commit(&oid, &sb);
+	else if (lookup_blob(&oid))
+		describe_blob(oid, &sb);
+	else
+		die(_("%s is neither a commit nor blob"), arg);
+
+	puts(sb.buf);
 
 	if (!last_one)
 		clear_commit_marks(cmit, -1);
+
+	strbuf_release(&sb);
 }
 
 int cmd_describe(int argc, const char **argv, const char *prefix)