diff --git a/builtin/fast-export.c b/builtin/fast-export.c
index 95e8e89e81f..8e2caf72819 100644
--- a/builtin/fast-export.c
+++ b/builtin/fast-export.c
@@ -312,7 +312,7 @@ static void export_blob(const struct object_id *oid)
 		if (!buf)
 			die("could not read blob %s", oid_to_hex(oid));
 		if (check_object_signature(the_repository, oid, buf, size,
-					   type_name(type)) < 0)
+					   type_name(type), NULL) < 0)
 			die("oid mismatch in blob %s", oid_to_hex(oid));
 		object = parse_object_buffer(the_repository, oid, type,
 					     size, buf, &eaten);
diff --git a/builtin/fsck.c b/builtin/fsck.c
index b42b6fe21f7..30a516da29e 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -593,18 +593,43 @@ static void get_default_heads(void)
 	}
 }
 
+struct for_each_loose_cb
+{
+	struct progress *progress;
+	struct strbuf obj_type;
+};
+
 static int fsck_loose(const struct object_id *oid, const char *path, void *data)
 {
+	struct for_each_loose_cb *cb_data = data;
 	struct object *obj;
-	enum object_type type;
+	enum object_type type = OBJ_NONE;
 	unsigned long size;
 	void *contents;
 	int eaten;
+	struct object_info oi = OBJECT_INFO_INIT;
+	struct object_id real_oid = *null_oid();
+	int err = 0;
 
-	if (read_loose_object(path, oid, &type, &size, &contents) < 0) {
+	strbuf_reset(&cb_data->obj_type);
+	oi.type_name = &cb_data->obj_type;
+	oi.sizep = &size;
+	oi.typep = &type;
+
+	if (read_loose_object(path, oid, &real_oid, &contents, &oi) < 0) {
+		if (contents && !oideq(&real_oid, oid))
+			err = error(_("%s: hash-path mismatch, found at: %s"),
+				    oid_to_hex(&real_oid), path);
+		else
+			err = error(_("%s: object corrupt or missing: %s"),
+				    oid_to_hex(oid), path);
+	}
+	if (type != OBJ_NONE && type < 0)
+		err = error(_("%s: object is of unknown type '%s': %s"),
+			    oid_to_hex(&real_oid), cb_data->obj_type.buf,
+			    path);
+	if (err < 0) {
 		errors_found |= ERROR_OBJECT;
-		error(_("%s: object corrupt or missing: %s"),
-		      oid_to_hex(oid), path);
 		return 0; /* keep checking other objects */
 	}
 
@@ -640,8 +665,10 @@ static int fsck_cruft(const char *basename, const char *path, void *data)
 	return 0;
 }
 
-static int fsck_subdir(unsigned int nr, const char *path, void *progress)
+static int fsck_subdir(unsigned int nr, const char *path, void *data)
 {
+	struct for_each_loose_cb *cb_data = data;
+	struct progress *progress = cb_data->progress;
 	display_progress(progress, nr + 1);
 	return 0;
 }
@@ -649,6 +676,10 @@ static int fsck_subdir(unsigned int nr, const char *path, void *progress)
 static void fsck_object_dir(const char *path)
 {
 	struct progress *progress = NULL;
+	struct for_each_loose_cb cb_data = {
+		.obj_type = STRBUF_INIT,
+		.progress = progress,
+	};
 
 	if (verbose)
 		fprintf_ln(stderr, _("Checking object directory"));
@@ -657,9 +688,10 @@ static void fsck_object_dir(const char *path)
 		progress = start_progress(_("Checking object directories"), 256);
 
 	for_each_loose_file_in_objdir(path, fsck_loose, fsck_cruft, fsck_subdir,
-				      progress);
+				      &cb_data);
 	display_progress(progress, 256);
 	stop_progress(&progress);
+	strbuf_release(&cb_data.obj_type);
 }
 
 static int fsck_head_link(const char *head_ref_name,
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 7ce69c087ec..15ae406e6b7 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1415,7 +1415,7 @@ static void fix_unresolved_deltas(struct hashfile *f)
 
 		if (check_object_signature(the_repository, &d->oid,
 					   data, size,
-					   type_name(type)))
+					   type_name(type), NULL))
 			die(_("local object %s is corrupt"), oid_to_hex(&d->oid));
 
 		/*
diff --git a/builtin/mktag.c b/builtin/mktag.c
index dddcccdd368..3b2dbbb37e6 100644
--- a/builtin/mktag.c
+++ b/builtin/mktag.c
@@ -62,7 +62,8 @@ static int verify_object_in_tag(struct object_id *tagged_oid, int *tagged_type)
 
 	repl = lookup_replace_object(the_repository, tagged_oid);
 	ret = check_object_signature(the_repository, repl,
-				     buffer, size, type_name(*tagged_type));
+				     buffer, size, type_name(*tagged_type),
+				     NULL);
 	free(buffer);
 
 	return ret;
diff --git a/cache.h b/cache.h
index d092820c943..acb67dbd642 100644
--- a/cache.h
+++ b/cache.h
@@ -1268,11 +1268,50 @@ char *xdg_cache_home(const char *filename);
 
 int git_open_cloexec(const char *name, int flags);
 #define git_open(name) git_open_cloexec(name, O_RDONLY)
-int unpack_loose_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz);
-int parse_loose_header(const char *hdr, unsigned long *sizep);
+
+/**
+ * unpack_loose_header() initializes the data stream needed to unpack
+ * a loose object header.
+ *
+ * Returns:
+ *
+ * - ULHR_OK on success
+ * - ULHR_BAD on error
+ * - ULHR_TOO_LONG if the header was too long
+ *
+ * It will only parse up to MAX_HEADER_LEN bytes unless an optional
+ * "hdrbuf" argument is non-NULL. This is intended for use with
+ * OBJECT_INFO_ALLOW_UNKNOWN_TYPE to extract the bad type for (error)
+ * reporting. The full header will be extracted to "hdrbuf" for use
+ * with parse_loose_header(), ULHR_TOO_LONG will still be returned
+ * from this function to indicate that the header was too long.
+ */
+enum unpack_loose_header_result {
+	ULHR_OK,
+	ULHR_BAD,
+	ULHR_TOO_LONG,
+};
+enum unpack_loose_header_result unpack_loose_header(git_zstream *stream,
+						    unsigned char *map,
+						    unsigned long mapsize,
+						    void *buffer,
+						    unsigned long bufsiz,
+						    struct strbuf *hdrbuf);
+
+/**
+ * parse_loose_header() parses the starting "<type> <len>\0" of an
+ * object. If it doesn't follow that format -1 is returned. To check
+ * the validity of the <type> populate the "typep" in the "struct
+ * object_info". It will be OBJ_BAD if the object type is unknown. The
+ * parsed <len> can be retrieved via "oi->sizep", and from there
+ * passed to unpack_loose_rest().
+ */
+struct object_info;
+int parse_loose_header(const char *hdr, struct object_info *oi);
 
 int check_object_signature(struct repository *r, const struct object_id *oid,
-			   void *buf, unsigned long size, const char *type);
+			   void *buf, unsigned long size, const char *type,
+			   struct object_id *real_oidp);
 
 int finalize_object_file(const char *tmpfile, const char *filename);
 
diff --git a/object-file.c b/object-file.c
index 112d9b4badc..8b35fd85bf3 100644
--- a/object-file.c
+++ b/object-file.c
@@ -1016,9 +1016,11 @@ void *xmmap(void *start, size_t length,
  * the streaming interface and rehash it to do the same.
  */
 int check_object_signature(struct repository *r, const struct object_id *oid,
-			   void *map, unsigned long size, const char *type)
+			   void *map, unsigned long size, const char *type,
+			   struct object_id *real_oidp)
 {
-	struct object_id real_oid;
+	struct object_id tmp;
+	struct object_id *real_oid = real_oidp ? real_oidp : &tmp;
 	enum object_type obj_type;
 	struct git_istream *st;
 	git_hash_ctx c;
@@ -1026,8 +1028,8 @@ int check_object_signature(struct repository *r, const struct object_id *oid,
 	int hdrlen;
 
 	if (map) {
-		hash_object_file(r->hash_algo, map, size, type, &real_oid);
-		return !oideq(oid, &real_oid) ? -1 : 0;
+		hash_object_file(r->hash_algo, map, size, type, real_oid);
+		return !oideq(oid, real_oid) ? -1 : 0;
 	}
 
 	st = open_istream(r, oid, &obj_type, &size, NULL);
@@ -1052,9 +1054,9 @@ int check_object_signature(struct repository *r, const struct object_id *oid,
 			break;
 		r->hash_algo->update_fn(&c, buf, readlen);
 	}
-	r->hash_algo->final_oid_fn(&real_oid, &c);
+	r->hash_algo->final_oid_fn(real_oid, &c);
 	close_istream(st);
-	return !oideq(oid, &real_oid) ? -1 : 0;
+	return !oideq(oid, real_oid) ? -1 : 0;
 }
 
 int git_open_cloexec(const char *name, int flags)
@@ -1187,11 +1189,14 @@ void *map_loose_object(struct repository *r,
 	return map_loose_object_1(r, NULL, oid, size);
 }
 
-static int unpack_loose_short_header(git_zstream *stream,
-				     unsigned char *map, unsigned long mapsize,
-				     void *buffer, unsigned long bufsiz)
+enum unpack_loose_header_result unpack_loose_header(git_zstream *stream,
+						    unsigned char *map,
+						    unsigned long mapsize,
+						    void *buffer,
+						    unsigned long bufsiz,
+						    struct strbuf *header)
 {
-	int ret;
+	int status;
 
 	/* Get the data stream */
 	memset(stream, 0, sizeof(*stream));
@@ -1202,43 +1207,24 @@ static int unpack_loose_short_header(git_zstream *stream,
 
 	git_inflate_init(stream);
 	obj_read_unlock();
-	ret = git_inflate(stream, 0);
+	status = git_inflate(stream, 0);
 	obj_read_lock();
-
-	return ret;
-}
-
-int unpack_loose_header(git_zstream *stream,
-			unsigned char *map, unsigned long mapsize,
-			void *buffer, unsigned long bufsiz)
-{
-	int status = unpack_loose_short_header(stream, map, mapsize,
-					       buffer, bufsiz);
-
 	if (status < Z_OK)
-		return status;
-
-	/* Make sure we have the terminating NUL */
-	if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
-		return -1;
-	return 0;
-}
-
-static int unpack_loose_header_to_strbuf(git_zstream *stream, unsigned char *map,
-					 unsigned long mapsize, void *buffer,
-					 unsigned long bufsiz, struct strbuf *header)
-{
-	int status;
-
-	status = unpack_loose_short_header(stream, map, mapsize, buffer, bufsiz);
-	if (status < Z_OK)
-		return -1;
+		return ULHR_BAD;
 
 	/*
 	 * Check if entire header is unpacked in the first iteration.
 	 */
 	if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
-		return 0;
+		return ULHR_OK;
+
+	/*
+	 * We have a header longer than MAX_HEADER_LEN. The "header"
+	 * here is only non-NULL when we run "cat-file
+	 * --allow-unknown-type".
+	 */
+	if (!header)
+		return ULHR_TOO_LONG;
 
 	/*
 	 * buffer[0..bufsiz] was not large enough.  Copy the partial
@@ -1259,7 +1245,7 @@ static int unpack_loose_header_to_strbuf(git_zstream *stream, unsigned char *map
 		stream->next_out = buffer;
 		stream->avail_out = bufsiz;
 	} while (status != Z_STREAM_END);
-	return -1;
+	return ULHR_TOO_LONG;
 }
 
 static void *unpack_loose_rest(git_zstream *stream,
@@ -1317,8 +1303,7 @@ static void *unpack_loose_rest(git_zstream *stream,
  * too permissive for what we want to check. So do an anal
  * object header parse by hand.
  */
-static int parse_loose_header_extended(const char *hdr, struct object_info *oi,
-				       unsigned int flags)
+int parse_loose_header(const char *hdr, struct object_info *oi)
 {
 	const char *type_buf = hdr;
 	unsigned long size;
@@ -1340,15 +1325,6 @@ static int parse_loose_header_extended(const char *hdr, struct object_info *oi,
 	type = type_from_string_gently(type_buf, type_len, 1);
 	if (oi->type_name)
 		strbuf_add(oi->type_name, type_buf, type_len);
-	/*
-	 * Set type to 0 if its an unknown object and
-	 * we're obtaining the type using '--allow-unknown-type'
-	 * option.
-	 */
-	if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
-		type = 0;
-	else if (type < 0)
-		die(_("invalid object type"));
 	if (oi->typep)
 		*oi->typep = type;
 
@@ -1375,15 +1351,14 @@ static int parse_loose_header_extended(const char *hdr, struct object_info *oi,
 	/*
 	 * The length must be followed by a zero byte
 	 */
-	return *hdr ? -1 : type;
-}
+	if (*hdr)
+		return -1;
 
-int parse_loose_header(const char *hdr, unsigned long *sizep)
-{
-	struct object_info oi = OBJECT_INFO_INIT;
-
-	oi.sizep = sizep;
-	return parse_loose_header_extended(hdr, &oi, 0);
+	/*
+	 * The format is valid, but the type may still be bogus. The
+	 * Caller needs to check its oi->typep.
+	 */
+	return 0;
 }
 
 static int loose_object_info(struct repository *r,
@@ -1397,6 +1372,8 @@ static int loose_object_info(struct repository *r,
 	char hdr[MAX_HEADER_LEN];
 	struct strbuf hdrbuf = STRBUF_INIT;
 	unsigned long size_scratch;
+	enum object_type type_scratch;
+	int allow_unknown = flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE;
 
 	if (oi->delta_base_oid)
 		oidclr(oi->delta_base_oid);
@@ -1427,43 +1404,48 @@ static int loose_object_info(struct repository *r,
 
 	if (!oi->sizep)
 		oi->sizep = &size_scratch;
+	if (!oi->typep)
+		oi->typep = &type_scratch;
 
 	if (oi->disk_sizep)
 		*oi->disk_sizep = mapsize;
-	if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
-		if (unpack_loose_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
-			status = error(_("unable to unpack %s header with --allow-unknown-type"),
-				       oid_to_hex(oid));
-	} else if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
+
+	switch (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr),
+				    allow_unknown ? &hdrbuf : NULL)) {
+	case ULHR_OK:
+		if (parse_loose_header(hdrbuf.len ? hdrbuf.buf : hdr, oi) < 0)
+			status = error(_("unable to parse %s header"), oid_to_hex(oid));
+		else if (!allow_unknown && *oi->typep < 0)
+			die(_("invalid object type"));
+
+		if (!oi->contentp)
+			break;
+		*oi->contentp = unpack_loose_rest(&stream, hdr, *oi->sizep, oid);
+		if (*oi->contentp)
+			goto cleanup;
+
+		status = -1;
+		break;
+	case ULHR_BAD:
 		status = error(_("unable to unpack %s header"),
 			       oid_to_hex(oid));
-	if (status < 0)
-		; /* Do nothing */
-	else if (hdrbuf.len) {
-		if ((status = parse_loose_header_extended(hdrbuf.buf, oi, flags)) < 0)
-			status = error(_("unable to parse %s header with --allow-unknown-type"),
-				       oid_to_hex(oid));
-	} else if ((status = parse_loose_header_extended(hdr, oi, flags)) < 0)
-		status = error(_("unable to parse %s header"), oid_to_hex(oid));
-
-	if (status >= 0 && oi->contentp) {
-		*oi->contentp = unpack_loose_rest(&stream, hdr,
-						  *oi->sizep, oid);
-		if (!*oi->contentp) {
-			git_inflate_end(&stream);
-			status = -1;
-		}
-	} else
-		git_inflate_end(&stream);
+		break;
+	case ULHR_TOO_LONG:
+		status = error(_("header for %s too long, exceeds %d bytes"),
+			       oid_to_hex(oid), MAX_HEADER_LEN);
+		break;
+	}
 
+	git_inflate_end(&stream);
+cleanup:
 	munmap(map, mapsize);
-	if (status && oi->typep)
-		*oi->typep = status;
 	if (oi->sizep == &size_scratch)
 		oi->sizep = NULL;
 	strbuf_release(&hdrbuf);
+	if (oi->typep == &type_scratch)
+		oi->typep = NULL;
 	oi->whence = OI_LOOSE;
-	return (status < 0) ? status : 0;
+	return status;
 }
 
 int obj_read_use_lock = 0;
@@ -2524,17 +2506,16 @@ static int check_stream_oid(git_zstream *stream,
 
 int read_loose_object(const char *path,
 		      const struct object_id *expected_oid,
-		      enum object_type *type,
-		      unsigned long *size,
-		      void **contents)
+		      struct object_id *real_oid,
+		      void **contents,
+		      struct object_info *oi)
 {
 	int ret = -1;
 	void *map = NULL;
 	unsigned long mapsize;
 	git_zstream stream;
 	char hdr[MAX_HEADER_LEN];
-
-	*contents = NULL;
+	unsigned long *size = oi->sizep;
 
 	map = map_loose_object_1(the_repository, path, NULL, &mapsize);
 	if (!map) {
@@ -2542,19 +2523,19 @@ int read_loose_object(const char *path,
 		goto out;
 	}
 
-	if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
+	if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr),
+				NULL) < 0) {
 		error(_("unable to unpack header of %s"), path);
 		goto out;
 	}
 
-	*type = parse_loose_header(hdr, size);
-	if (*type < 0) {
+	if (parse_loose_header(hdr, oi) < 0) {
 		error(_("unable to parse header of %s"), path);
 		git_inflate_end(&stream);
 		goto out;
 	}
 
-	if (*type == OBJ_BLOB && *size > big_file_threshold) {
+	if (*oi->typep == OBJ_BLOB && *size > big_file_threshold) {
 		if (check_stream_oid(&stream, hdr, *size, path, expected_oid) < 0)
 			goto out;
 	} else {
@@ -2565,10 +2546,7 @@ int read_loose_object(const char *path,
 			goto out;
 		}
 		if (check_object_signature(the_repository, expected_oid,
-					   *contents, *size,
-					   type_name(*type))) {
-			error(_("hash mismatch for %s (expected %s)"), path,
-			      oid_to_hex(expected_oid));
+					   *contents, *size, oi->type_name->buf, real_oid)) {
 			free(*contents);
 			goto out;
 		}
diff --git a/object-store.h b/object-store.h
index 1e647a5be30..07387dc48f1 100644
--- a/object-store.h
+++ b/object-store.h
@@ -245,6 +245,7 @@ int force_object_loose(const struct object_id *oid, time_t mtime);
 
 /*
  * Open the loose object at path, check its hash, and return the contents,
+ * use the "oi" argument to assert things about the object, or e.g. populate its
  * type, and size. If the object is a blob, then "contents" may return NULL,
  * to allow streaming of large blobs.
  *
@@ -252,9 +253,9 @@ int force_object_loose(const struct object_id *oid, time_t mtime);
  */
 int read_loose_object(const char *path,
 		      const struct object_id *expected_oid,
-		      enum object_type *type,
-		      unsigned long *size,
-		      void **contents);
+		      struct object_id *real_oid,
+		      void **contents,
+		      struct object_info *oi);
 
 /* Retry packed storage after checking packed and loose storage */
 #define HAS_OBJECT_RECHECK_PACKED 1
diff --git a/object.c b/object.c
index 4e85955a941..23a24e678a8 100644
--- a/object.c
+++ b/object.c
@@ -279,7 +279,7 @@ struct object *parse_object(struct repository *r, const struct object_id *oid)
 	if ((obj && obj->type == OBJ_BLOB && repo_has_object_file(r, oid)) ||
 	    (!obj && repo_has_object_file(r, oid) &&
 	     oid_object_info(r, oid, NULL) == OBJ_BLOB)) {
-		if (check_object_signature(r, repl, NULL, 0, NULL) < 0) {
+		if (check_object_signature(r, repl, NULL, 0, NULL, NULL) < 0) {
 			error(_("hash mismatch %s"), oid_to_hex(oid));
 			return NULL;
 		}
@@ -290,7 +290,7 @@ struct object *parse_object(struct repository *r, const struct object_id *oid)
 	buffer = repo_read_object_file(r, oid, &type, &size);
 	if (buffer) {
 		if (check_object_signature(r, repl, buffer, size,
-					   type_name(type)) < 0) {
+					   type_name(type), NULL) < 0) {
 			free(buffer);
 			error(_("hash mismatch %s"), oid_to_hex(repl));
 			return NULL;
diff --git a/pack-check.c b/pack-check.c
index c8e560d71ab..3f418e3a6af 100644
--- a/pack-check.c
+++ b/pack-check.c
@@ -142,7 +142,8 @@ static int verify_packfile(struct repository *r,
 			err = error("cannot unpack %s from %s at offset %"PRIuMAX"",
 				    oid_to_hex(&oid), p->pack_name,
 				    (uintmax_t)entries[i].offset);
-		else if (check_object_signature(r, &oid, data, size, type_name(type)))
+		else if (check_object_signature(r, &oid, data, size,
+						type_name(type), NULL))
 			err = error("packed %s from %s is corrupt",
 				    oid_to_hex(&oid), p->pack_name);
 		else if (fn) {
diff --git a/streaming.c b/streaming.c
index 5f480ad50c4..fe54665d86e 100644
--- a/streaming.c
+++ b/streaming.c
@@ -223,19 +223,24 @@ static int open_istream_loose(struct git_istream *st, struct repository *r,
 			      const struct object_id *oid,
 			      enum object_type *type)
 {
+	struct object_info oi = OBJECT_INFO_INIT;
+	oi.sizep = &st->size;
+	oi.typep = type;
+
 	st->u.loose.mapped = map_loose_object(r, oid, &st->u.loose.mapsize);
 	if (!st->u.loose.mapped)
 		return -1;
-	if ((unpack_loose_header(&st->z,
-				 st->u.loose.mapped,
-				 st->u.loose.mapsize,
-				 st->u.loose.hdr,
-				 sizeof(st->u.loose.hdr)) < 0) ||
-	    (parse_loose_header(st->u.loose.hdr, &st->size) < 0)) {
-		git_inflate_end(&st->z);
-		munmap(st->u.loose.mapped, st->u.loose.mapsize);
-		return -1;
+	switch (unpack_loose_header(&st->z, st->u.loose.mapped,
+				    st->u.loose.mapsize, st->u.loose.hdr,
+				    sizeof(st->u.loose.hdr), NULL)) {
+	case ULHR_OK:
+		break;
+	case ULHR_BAD:
+	case ULHR_TOO_LONG:
+		goto error;
 	}
+	if (parse_loose_header(st->u.loose.hdr, &oi) < 0 || *type < 0)
+		goto error;
 
 	st->u.loose.hdr_used = strlen(st->u.loose.hdr) + 1;
 	st->u.loose.hdr_avail = st->z.total_out;
@@ -244,6 +249,10 @@ static int open_istream_loose(struct git_istream *st, struct repository *r,
 	st->read = read_istream_loose;
 
 	return 0;
+error:
+	git_inflate_end(&st->z);
+	munmap(st->u.loose.mapped, st->u.loose.mapsize);
+	return -1;
 }
 
 
diff --git a/t/oid-info/oid b/t/oid-info/oid
index a754970523c..7547d2c7903 100644
--- a/t/oid-info/oid
+++ b/t/oid-info/oid
@@ -27,3 +27,5 @@ numeric		sha1:0123456789012345678901234567890123456789
 numeric		sha256:0123456789012345678901234567890123456789012345678901234567890123
 deadbeef	sha1:deadbeefdeadbeefdeadbeefdeadbeefdeadbeef
 deadbeef	sha256:deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeef
+deadbeef_short	sha1:deadbeefdeadbeefdeadbeefdeadbeefdeadbee
+deadbeef_short	sha256:deadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbeefdeadbee
diff --git a/t/t1006-cat-file.sh b/t/t1006-cat-file.sh
index 4a753705ec2..658628375c8 100755
--- a/t/t1006-cat-file.sh
+++ b/t/t1006-cat-file.sh
@@ -315,46 +315,236 @@ test_expect_success '%(deltabase) reports packed delta bases' '
 	}
 '
 
-bogus_type="bogus"
-bogus_content="bogus"
-bogus_size=$(strlen "$bogus_content")
-bogus_sha1=$(echo_without_newline "$bogus_content" | git hash-object -t $bogus_type --literally -w --stdin)
+test_expect_success 'setup bogus data' '
+	bogus_short_type="bogus" &&
+	bogus_short_content="bogus" &&
+	bogus_short_size=$(strlen "$bogus_short_content") &&
+	bogus_short_sha1=$(echo_without_newline "$bogus_short_content" | git hash-object -t $bogus_short_type --literally -w --stdin) &&
+
+	bogus_long_type="abcdefghijklmnopqrstuvwxyz1234679" &&
+	bogus_long_content="bogus" &&
+	bogus_long_size=$(strlen "$bogus_long_content") &&
+	bogus_long_sha1=$(echo_without_newline "$bogus_long_content" | git hash-object -t $bogus_long_type --literally -w --stdin)
+'
+
+for arg1 in '' --allow-unknown-type
+do
+	for arg2 in -s -t -p
+	do
+		if test "$arg1" = "--allow-unknown-type" && test "$arg2" = "-p"
+		then
+			continue
+		fi
+
+
+		test_expect_success "cat-file $arg1 $arg2 error on bogus short OID" '
+			cat >expect <<-\EOF &&
+			fatal: invalid object type
+			EOF
+
+			if test "$arg1" = "--allow-unknown-type"
+			then
+				git cat-file $arg1 $arg2 $bogus_short_sha1
+			else
+				test_must_fail git cat-file $arg1 $arg2 $bogus_short_sha1 >out 2>actual &&
+				test_must_be_empty out &&
+				test_cmp expect actual
+			fi
+		'
+
+		test_expect_success "cat-file $arg1 $arg2 error on bogus full OID" '
+			if test "$arg2" = "-p"
+			then
+				cat >expect <<-EOF
+				error: header for $bogus_long_sha1 too long, exceeds 32 bytes
+				fatal: Not a valid object name $bogus_long_sha1
+				EOF
+			else
+				cat >expect <<-EOF
+				error: header for $bogus_long_sha1 too long, exceeds 32 bytes
+				fatal: git cat-file: could not get object info
+				EOF
+			fi &&
+
+			if test "$arg1" = "--allow-unknown-type"
+			then
+				git cat-file $arg1 $arg2 $bogus_short_sha1
+			else
+				test_must_fail git cat-file $arg1 $arg2 $bogus_long_sha1 >out 2>actual &&
+				test_must_be_empty out &&
+				test_cmp expect actual
+			fi
+		'
+
+		test_expect_success "cat-file $arg1 $arg2 error on missing short OID" '
+			cat >expect.err <<-EOF &&
+			fatal: Not a valid object name $(test_oid deadbeef_short)
+			EOF
+			test_must_fail git cat-file $arg1 $arg2 $(test_oid deadbeef_short) >out 2>err.actual &&
+			test_must_be_empty out
+		'
+
+		test_expect_success "cat-file $arg1 $arg2 error on missing full OID" '
+			if test "$arg2" = "-p"
+			then
+				cat >expect.err <<-EOF
+				fatal: Not a valid object name $(test_oid deadbeef)
+				EOF
+			else
+				cat >expect.err <<-\EOF
+				fatal: git cat-file: could not get object info
+				EOF
+			fi &&
+			test_must_fail git cat-file $arg1 $arg2 $(test_oid deadbeef) >out 2>err.actual &&
+			test_must_be_empty out &&
+			test_cmp expect.err err.actual
+		'
+	done
+done
+
+test_expect_success '-e is OK with a broken object without --allow-unknown-type' '
+	git cat-file -e $bogus_short_sha1
+'
+
+test_expect_success '-e can not be combined with --allow-unknown-type' '
+	test_expect_code 128 git cat-file -e --allow-unknown-type $bogus_short_sha1
+'
+
+test_expect_success '-p cannot print a broken object even with --allow-unknown-type' '
+	test_must_fail git cat-file -p $bogus_short_sha1 &&
+	test_expect_code 128 git cat-file -p --allow-unknown-type $bogus_short_sha1
+'
+
+test_expect_success '<type> <hash> does not work with objects of broken types' '
+	cat >err.expect <<-\EOF &&
+	fatal: invalid object type "bogus"
+	EOF
+	test_must_fail git cat-file $bogus_short_type $bogus_short_sha1 2>err.actual &&
+	test_cmp err.expect err.actual
+'
+
+test_expect_success 'broken types combined with --batch and --batch-check' '
+	echo $bogus_short_sha1 >bogus-oid &&
+
+	cat >err.expect <<-\EOF &&
+	fatal: invalid object type
+	EOF
+
+	test_must_fail git cat-file --batch <bogus-oid 2>err.actual &&
+	test_cmp err.expect err.actual &&
+
+	test_must_fail git cat-file --batch-check <bogus-oid 2>err.actual &&
+	test_cmp err.expect err.actual
+'
+
+test_expect_success 'the --batch and --batch-check options do not combine with --allow-unknown-type' '
+	test_expect_code 128 git cat-file --batch --allow-unknown-type <bogus-oid &&
+	test_expect_code 128 git cat-file --batch-check --allow-unknown-type <bogus-oid
+'
+
+test_expect_success 'the --allow-unknown-type option does not consider replacement refs' '
+	cat >expect <<-EOF &&
+	$bogus_short_type
+	EOF
+	git cat-file -t --allow-unknown-type $bogus_short_sha1 >actual &&
+	test_cmp expect actual &&
+
+	# Create it manually, as "git replace" will die on bogus
+	# types.
+	head=$(git rev-parse --verify HEAD) &&
+	test_when_finished "rm -rf .git/refs/replace" &&
+	mkdir -p .git/refs/replace &&
+	echo $head >.git/refs/replace/$bogus_short_sha1 &&
+
+	cat >expect <<-EOF &&
+	commit
+	EOF
+	git cat-file -t --allow-unknown-type $bogus_short_sha1 >actual &&
+	test_cmp expect actual
+'
 
 test_expect_success "Type of broken object is correct" '
-	echo $bogus_type >expect &&
-	git cat-file -t --allow-unknown-type $bogus_sha1 >actual &&
+	echo $bogus_short_type >expect &&
+	git cat-file -t --allow-unknown-type $bogus_short_sha1 >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success "Size of broken object is correct" '
-	echo $bogus_size >expect &&
-	git cat-file -s --allow-unknown-type $bogus_sha1 >actual &&
+	echo $bogus_short_size >expect &&
+	git cat-file -s --allow-unknown-type $bogus_short_sha1 >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success 'clean up broken object' '
-	rm .git/objects/$(test_oid_to_path $bogus_sha1)
+	rm .git/objects/$(test_oid_to_path $bogus_short_sha1)
 '
 
-bogus_type="abcdefghijklmnopqrstuvwxyz1234679"
-bogus_content="bogus"
-bogus_size=$(strlen "$bogus_content")
-bogus_sha1=$(echo_without_newline "$bogus_content" | git hash-object -t $bogus_type --literally -w --stdin)
-
 test_expect_success "Type of broken object is correct when type is large" '
-	echo $bogus_type >expect &&
-	git cat-file -t --allow-unknown-type $bogus_sha1 >actual &&
+	echo $bogus_long_type >expect &&
+	git cat-file -t --allow-unknown-type $bogus_long_sha1 >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success "Size of large broken object is correct when type is large" '
-	echo $bogus_size >expect &&
-	git cat-file -s --allow-unknown-type $bogus_sha1 >actual &&
+	echo $bogus_long_size >expect &&
+	git cat-file -s --allow-unknown-type $bogus_long_sha1 >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success 'clean up broken object' '
-	rm .git/objects/$(test_oid_to_path $bogus_sha1)
+	rm .git/objects/$(test_oid_to_path $bogus_long_sha1)
+'
+
+test_expect_success 'cat-file -t and -s on corrupt loose object' '
+	git init --bare corrupt-loose.git &&
+	(
+		cd corrupt-loose.git &&
+
+		# Setup and create the empty blob and its path
+		empty_path=$(git rev-parse --git-path objects/$(test_oid_to_path "$EMPTY_BLOB")) &&
+		git hash-object -w --stdin </dev/null &&
+
+		# Create another blob and its path
+		echo other >other.blob &&
+		other_blob=$(git hash-object -w --stdin <other.blob) &&
+		other_path=$(git rev-parse --git-path objects/$(test_oid_to_path "$other_blob")) &&
+
+		# Before the swap the size is 0
+		cat >out.expect <<-EOF &&
+		0
+		EOF
+		git cat-file -s "$EMPTY_BLOB" >out.actual 2>err.actual &&
+		test_must_be_empty err.actual &&
+		test_cmp out.expect out.actual &&
+
+		# Swap the two to corrupt the repository
+		mv -f "$other_path" "$empty_path" &&
+		test_must_fail git fsck 2>err.fsck &&
+		grep "hash-path mismatch" err.fsck &&
+
+		# confirm that cat-file is reading the new swapped-in
+		# blob...
+		cat >out.expect <<-EOF &&
+		blob
+		EOF
+		git cat-file -t "$EMPTY_BLOB" >out.actual 2>err.actual &&
+		test_must_be_empty err.actual &&
+		test_cmp out.expect out.actual &&
+
+		# ... since it has a different size now.
+		cat >out.expect <<-EOF &&
+		6
+		EOF
+		git cat-file -s "$EMPTY_BLOB" >out.actual 2>err.actual &&
+		test_must_be_empty err.actual &&
+		test_cmp out.expect out.actual &&
+
+		# So far "cat-file" has been happy to spew the found
+		# content out as-is. Try to make it zlib-invalid.
+		mv -f other.blob "$empty_path" &&
+		test_must_fail git fsck 2>err.fsck &&
+		grep "^error: inflate: data stream error (" err.fsck
+	)
 '
 
 # Tests for git cat-file --follow-symlinks
diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index 5071ac63a5b..6337236fd82 100755
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -48,24 +48,70 @@ remove_object () {
 	rm "$(sha1_file "$1")"
 }
 
-test_expect_success 'object with bad sha1' '
-	sha=$(echo blob | git hash-object -w --stdin) &&
-	old=$(test_oid_to_path "$sha") &&
-	new=$(dirname $old)/$(test_oid ff_2) &&
-	sha="$(dirname $new)$(basename $new)" &&
-	mv .git/objects/$old .git/objects/$new &&
-	test_when_finished "remove_object $sha" &&
-	git update-index --add --cacheinfo 100644 $sha foo &&
-	test_when_finished "git read-tree -u --reset HEAD" &&
-	tree=$(git write-tree) &&
-	test_when_finished "remove_object $tree" &&
-	cmt=$(echo bogus | git commit-tree $tree) &&
-	test_when_finished "remove_object $cmt" &&
-	git update-ref refs/heads/bogus $cmt &&
-	test_when_finished "git update-ref -d refs/heads/bogus" &&
+test_expect_success 'object with hash mismatch' '
+	git init --bare hash-mismatch &&
+	(
+		cd hash-mismatch &&
 
-	test_must_fail git fsck 2>out &&
-	test_i18ngrep "$sha.*corrupt" out
+		oid=$(echo blob | git hash-object -w --stdin) &&
+		oldoid=$oid &&
+		old=$(test_oid_to_path "$oid") &&
+		new=$(dirname $old)/$(test_oid ff_2) &&
+		oid="$(dirname $new)$(basename $new)" &&
+
+		mv objects/$old objects/$new &&
+		git update-index --add --cacheinfo 100644 $oid foo &&
+		tree=$(git write-tree) &&
+		cmt=$(echo bogus | git commit-tree $tree) &&
+		git update-ref refs/heads/bogus $cmt &&
+
+		test_must_fail git fsck 2>out &&
+		grep "$oldoid: hash-path mismatch, found at: .*$new" out
+	)
+'
+
+test_expect_success 'object with hash and type mismatch' '
+	git init --bare hash-type-mismatch &&
+	(
+		cd hash-type-mismatch &&
+
+		oid=$(echo blob | git hash-object -w --stdin -t garbage --literally) &&
+		oldoid=$oid &&
+		old=$(test_oid_to_path "$oid") &&
+		new=$(dirname $old)/$(test_oid ff_2) &&
+		oid="$(dirname $new)$(basename $new)" &&
+
+		mv objects/$old objects/$new &&
+		git update-index --add --cacheinfo 100644 $oid foo &&
+		tree=$(git write-tree) &&
+		cmt=$(echo bogus | git commit-tree $tree) &&
+		git update-ref refs/heads/bogus $cmt &&
+
+
+		test_must_fail git fsck 2>out &&
+		grep "^error: $oldoid: hash-path mismatch, found at: .*$new" out &&
+		grep "^error: $oldoid: object is of unknown type '"'"'garbage'"'"'" out
+	)
+'
+
+test_expect_success POSIXPERM 'zlib corrupt loose object output ' '
+	git init --bare corrupt-loose-output &&
+	(
+		cd corrupt-loose-output &&
+		oid=$(git hash-object -w --stdin --literally </dev/null) &&
+		oidf=objects/$(test_oid_to_path "$oid") &&
+		chmod 755 $oidf &&
+		echo extra garbage >>$oidf &&
+
+		cat >expect.error <<-EOF &&
+		error: garbage at end of loose object '\''$oid'\''
+		error: unable to unpack contents of ./$oidf
+		error: $oid: object corrupt or missing: ./$oidf
+		EOF
+		test_must_fail git fsck 2>actual &&
+		grep ^error: actual >error &&
+		test_cmp expect.error error
+	)
 '
 
 test_expect_success 'branch pointing to non-commit' '
@@ -865,4 +911,21 @@ test_expect_success 'detect corrupt index file in fsck' '
 	test_i18ngrep "bad index file" errors
 '
 
+test_expect_success 'fsck error and recovery on invalid object type' '
+	git init --bare garbage-type &&
+	(
+		cd garbage-type &&
+
+		garbage_blob=$(git hash-object --stdin -w -t garbage --literally </dev/null) &&
+
+		cat >err.expect <<-\EOF &&
+		fatal: invalid object type
+		EOF
+		test_must_fail git fsck >out 2>err &&
+		grep -e "^error" -e "^fatal" err >errors &&
+		test_line_count = 1 errors &&
+		grep "$garbage_blob: object is of unknown type '"'"'garbage'"'"':" err
+	)
+'
+
 test_done