Merge branch 'jk/cat-file-buffered-batch-all'

"git cat-file --batch-all" has been sped up, by taking advantage
of the fact that it does not have to read a list of objects, in two
ways.

* jk/cat-file-buffered-batch-all:
  cat-file: default to --buffer when --batch-all-objects is used
  cat-file: avoid noop calls to sha1_object_info_extended

builtin/cat-file.c

@@ -154,6 +154,13 @@ struct expand_data {
 	 * elements above, so you can retrieve the response from there.
 	 */
 	struct object_info info;
+
+	/*
+	 * This flag will be true if the requested batch format and options
+	 * don't require us to call sha1_object_info, which can then be
+	 * optimized out.
+	 */
+	unsigned skip_object_info : 1;
 };
 
 static int is_atom(const char *atom, const char *s, int slen)
@@ -258,7 +265,8 @@ static void batch_object_write(const char *obj_name, struct batch_options *opt,
 {
 	struct strbuf buf = STRBUF_INIT;
 
-	if (sha1_object_info_extended(data->sha1, &data->info, LOOKUP_REPLACE_OBJECT) < 0) {
+	if (!data->skip_object_info &&
+	    sha1_object_info_extended(data->sha1, &data->info, LOOKUP_REPLACE_OBJECT) < 0) {
 		printf("%s missing\n", obj_name ? obj_name : sha1_to_hex(data->sha1));
 		fflush(stdout);
 		return;
@@ -369,6 +377,13 @@ static int batch_objects(struct batch_options *opt)
 	strbuf_expand(&buf, opt->format, expand_format, &data);
 	data.mark_query = 0;
 
+	if (opt->all_objects) {
+		struct object_info empty;
+		memset(&empty, 0, sizeof(empty));
+		if (!memcmp(&data.info, &empty, sizeof(empty)))
+			data.skip_object_info = 1;
+	}
+
 	/*
 	 * If we are printing out the object, then always fill in the type,
 	 * since we will want to decide whether or not to stream.
@@ -489,6 +504,7 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
 
 	git_config(git_cat_file_config, NULL);
 
+	batch.buffer_output = -1;
 	argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 
 	if (opt) {
@@ -512,6 +528,9 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
 		usage_with_options(cat_file_usage, options);
 	}
 
+	if (batch.buffer_output < 0)
+		batch.buffer_output = batch.all_objects;
+
 	if (batch.enabled)
 		return batch_objects(&batch);