4 files changed, 73 insertions, 25 deletions
diff --git a/builtin/check-mailmap.c b/builtin/check-mailmap.c
index b8a05b8e07..2334b57222 100644
--- a/builtin/check-mailmap.c
+++ b/builtin/check-mailmap.c
@@ -9,6 +9,7 @@
 #include "write-or-die.h"
 
 static int use_stdin;
+static const char *mailmap_file, *mailmap_blob;
 static const char * const check_mailmap_usage[] = {
 N_("git check-mailmap [<options>] <contact>..."),
 NULL
@@ -16,6 +17,8 @@ NULL
 
 static const struct option check_mailmap_options[] = {
 	OPT_BOOL(0, "stdin", &use_stdin, N_("also read contacts from stdin")),
+	OPT_FILENAME(0, "mailmap-file", &mailmap_file, N_("read additional mailmap entries from file")),
+	OPT_STRING(0, "mailmap-blob", &mailmap_blob, N_("blob"), N_("read additional mailmap entries from blob")),
 	OPT_END()
 };
 
@@ -25,13 +28,17 @@ static void check_mailmap(struct string_list *mailmap, const char *contact)
 	size_t namelen, maillen;
 	struct ident_split ident;
 
-	if (split_ident_line(&ident, contact, strlen(contact)))
-		die(_("unable to parse contact: %s"), contact);
-
-	name = ident.name_begin;
-	namelen = ident.name_end - ident.name_begin;
-	mail = ident.mail_begin;
-	maillen = ident.mail_end - ident.mail_begin;
+	if (!split_ident_line(&ident, contact, strlen(contact))) {
+		name = ident.name_begin;
+		namelen = ident.name_end - ident.name_begin;
+		mail = ident.mail_begin;
+		maillen = ident.mail_end - ident.mail_begin;
+	} else {
+		name = NULL;
+		namelen = 0;
+		mail = contact;
+		maillen = strlen(contact);
+	}
 
 	map_user(mailmap, &mail, &maillen, &name, &namelen);
 
@@ -52,6 +59,10 @@ int cmd_check_mailmap(int argc, const char **argv, const char *prefix)
 		die(_("no contacts specified"));
 
 	read_mailmap(&mailmap);
+	if (mailmap_blob)
+		read_mailmap_blob(&mailmap, mailmap_blob);
+	if (mailmap_file)
+		read_mailmap_file(&mailmap, mailmap_file, 0);
 
 	for (i = 0; i < argc; ++i)
 		check_mailmap(&mailmap, argv[i]);
diff --git a/builtin/gc.c b/builtin/gc.c
index 427faf1cfe..7dac971405 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -260,7 +260,7 @@ static int pack_refs_condition(UNUSED struct gc_config *cfg)
 	return 1;
 }
 
-static int maintenance_task_pack_refs(MAYBE_UNUSED struct maintenance_run_opts *opts,
+static int maintenance_task_pack_refs(struct maintenance_run_opts *opts,
 				      UNUSED struct gc_config *cfg)
 {
 	struct child_process cmd = CHILD_PROCESS_INIT;
@@ -967,7 +967,7 @@ static int dfs_on_ref(const char *refname UNUSED,
 	return result;
 }
 
-static int should_write_commit_graph(struct gc_config *cfg)
+static int should_write_commit_graph(struct gc_config *cfg UNUSED)
 {
 	int result;
 	struct cg_auto_data data;
@@ -1005,7 +1005,7 @@ static int run_write_commit_graph(struct maintenance_run_opts *opts)
 }
 
 static int maintenance_task_commit_graph(struct maintenance_run_opts *opts,
-					 struct gc_config *cfg)
+					 struct gc_config *cfg UNUSED)
 {
 	prepare_repo_settings(the_repository);
 	if (!the_repository->settings.core_commit_graph)
@@ -1040,7 +1040,7 @@ static int fetch_remote(struct remote *remote, void *cbdata)
 }
 
 static int maintenance_task_prefetch(struct maintenance_run_opts *opts,
-				     struct gc_config *cfg)
+				     struct gc_config *cfg UNUSED)
 {
 	if (for_each_remote(fetch_remote, opts)) {
 		error(_("failed to prefetch remotes"));
@@ -1051,7 +1051,7 @@ static int maintenance_task_prefetch(struct maintenance_run_opts *opts,
 }
 
 static int maintenance_task_gc(struct maintenance_run_opts *opts,
-			       struct gc_config *cfg)
+			       struct gc_config *cfg UNUSED)
 {
 	struct child_process child = CHILD_PROCESS_INIT;
 
@@ -1100,7 +1100,7 @@ static int loose_object_count(const struct object_id *oid UNUSED,
 	return 0;
 }
 
-static int loose_object_auto_condition(struct gc_config *cfg)
+static int loose_object_auto_condition(struct gc_config *cfg UNUSED)
 {
 	int count = 0;
 
@@ -1192,12 +1192,12 @@ static int pack_loose(struct maintenance_run_opts *opts)
 }
 
 static int maintenance_task_loose_objects(struct maintenance_run_opts *opts,
-					  struct gc_config *cfg)
+					  struct gc_config *cfg UNUSED)
 {
 	return prune_packed(opts) || pack_loose(opts);
 }
 
-static int incremental_repack_auto_condition(struct gc_config *cfg)
+static int incremental_repack_auto_condition(struct gc_config *cfg UNUSED)
 {
 	struct packed_git *p;
 	int incremental_repack_auto_limit = 10;
@@ -1317,7 +1317,7 @@ static int multi_pack_index_repack(struct maintenance_run_opts *opts)
 }
 
 static int maintenance_task_incremental_repack(struct maintenance_run_opts *opts,
-					       struct gc_config *cfg)
+					       struct gc_config *cfg UNUSED)
 {
 	prepare_repo_settings(the_repository);
 	if (!the_repository->settings.core_multi_pack_index) {
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index fd968d673d..763b01372a 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1868,6 +1868,15 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	if (!index_name && pack_name)
 		index_name = derive_filename(pack_name, "pack", "idx", &index_name_buf);
 
+	/*
+	 * Packfiles and indices do not carry enough information to be able to
+	 * identify their object hash. So when we are neither in a repository
+	 * nor has the user told us which object hash to use we have no other
+	 * choice but to guess the object hash.
+	 */
+	if (!the_repository->hash_algo)
+		repo_set_hash_algo(the_repository, GIT_HASH_SHA1);
+
 	opts.flags &= ~(WRITE_REV | WRITE_REV_VERIFY);
 	if (rev_index) {
 		opts.flags |= verify ? WRITE_REV_VERIFY : WRITE_REV;
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 778be80f56..c6e2852d3c 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -1072,7 +1072,7 @@ static void write_reused_pack_one(struct packed_git *reuse_packfile,
 		fixup = find_reused_offset(offset) -
 			find_reused_offset(base_offset);
 		if (fixup) {
-			unsigned char ofs_header[10];
+			unsigned char ofs_header[MAX_PACK_OBJECT_HEADER];
 			unsigned i, ofs_len;
 			off_t ofs = offset - base_offset - fixup;
 
@@ -1191,6 +1191,7 @@ static void write_reused_pack(struct bitmapped_pack *reuse_packfile,
 		size_t pos = (i * BITS_IN_EWORD);
 
 		for (offset = 0; offset < BITS_IN_EWORD; ++offset) {
+			uint32_t pack_pos;
 			if ((word >> offset) == 0)
 				break;
 
@@ -1199,14 +1200,41 @@ static void write_reused_pack(struct bitmapped_pack *reuse_packfile,
 				continue;
 			if (pos + offset >= reuse_packfile->bitmap_pos + reuse_packfile->bitmap_nr)
 				goto done;
-			/*
-			 * Can use bit positions directly, even for MIDX
-			 * bitmaps. See comment in try_partial_reuse()
-			 * for why.
-			 */
-			write_reused_pack_one(reuse_packfile->p,
-					      pos + offset - reuse_packfile->bitmap_pos,
-					      f, pack_start, &w_curs);
+
+			if (reuse_packfile->bitmap_pos) {
+				/*
+				 * When doing multi-pack reuse on a
+				 * non-preferred pack, translate bit positions
+				 * from the MIDX pseudo-pack order back to their
+				 * pack-relative positions before attempting
+				 * reuse.
+				 */
+				struct multi_pack_index *m = reuse_packfile->from_midx;
+				uint32_t midx_pos;
+				off_t pack_ofs;
+
+				if (!m)
+					BUG("non-zero bitmap position without MIDX");
+
+				midx_pos = pack_pos_to_midx(m, pos + offset);
+				pack_ofs = nth_midxed_offset(m, midx_pos);
+
+				if (offset_to_pack_pos(reuse_packfile->p,
+						       pack_ofs, &pack_pos) < 0)
+					BUG("could not find expected object at offset %"PRIuMAX" in pack %s",
+					    (uintmax_t)pack_ofs,
+					    pack_basename(reuse_packfile->p));
+			} else {
+				/*
+				 * Can use bit positions directly, even for MIDX
+				 * bitmaps. See comment in try_partial_reuse()
+				 * for why.
+				 */
+				pack_pos = pos + offset;
+			}
+
+			write_reused_pack_one(reuse_packfile->p, pack_pos, f,
+					      pack_start, &w_curs);
 			display_progress(progress_state, ++written);
 		}
 	}