revision: introduce setup_revision_opt

So far the last parameter to setup_revisions() was to specify the default
ref when the command line did not give any (typically "HEAD").  This changes
it to take a pointer to a structure so that we can add other information without
touching too many codepaths in later patches.

There is no functionality change.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-log.c

@@ -32,7 +32,7 @@ static const char * const builtin_log_usage =
 	"   or: git show [options] <object>...";
 
 static void cmd_log_init(int argc, const char **argv, const char *prefix,
-		      struct rev_info *rev)
+			 struct rev_info *rev, struct setup_revision_opt *opt)
 {
 	int i;
 	int decoration_style = 0;
@@ -56,7 +56,7 @@ static void cmd_log_init(int argc, const char **argv, const char *prefix,
 	 */
 	if (argc == 2 && !strcmp(argv[1], "-h"))
 		usage(builtin_log_usage);
-	argc = setup_revisions(argc, argv, rev, "HEAD");
+	argc = setup_revisions(argc, argv, rev, opt);
 
 	if (!rev->show_notes_given && !rev->pretty_given)
 		rev->show_notes = 1;
@@ -262,6 +262,7 @@ static int git_log_config(const char *var, const char *value, void *cb)
 int cmd_whatchanged(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info rev;
+	struct setup_revision_opt opt;
 
 	git_config(git_log_config, NULL);
 
@@ -271,7 +272,9 @@ int cmd_whatchanged(int argc, const char **argv, const char *prefix)
 	init_revisions(&rev, prefix);
 	rev.diff = 1;
 	rev.simplify_history = 0;
-	cmd_log_init(argc, argv, prefix, &rev);
+	memset(&opt, 0, sizeof(opt));
+	opt.def = "HEAD";
+	cmd_log_init(argc, argv, prefix, &rev, &opt);
 	if (!rev.diffopt.output_format)
 		rev.diffopt.output_format = DIFF_FORMAT_RAW;
 	return cmd_log_walk(&rev);
@@ -328,6 +331,7 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info rev;
 	struct object_array_entry *objects;
+	struct setup_revision_opt opt;
 	int i, count, ret = 0;
 
 	git_config(git_log_config, NULL);
@@ -342,7 +346,9 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 	rev.always_show_header = 1;
 	rev.ignore_merges = 0;
 	rev.no_walk = 1;
-	cmd_log_init(argc, argv, prefix, &rev);
+	memset(&opt, 0, sizeof(opt));
+	opt.def = "HEAD";
+	cmd_log_init(argc, argv, prefix, &rev, &opt);
 
 	count = rev.pending.nr;
 	objects = rev.pending.objects;
@@ -405,6 +411,7 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info rev;
+	struct setup_revision_opt opt;
 
 	git_config(git_log_config, NULL);
 
@@ -415,7 +422,9 @@ int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 	init_reflog_walk(&rev.reflog_info);
 	rev.abbrev_commit = 1;
 	rev.verbose_header = 1;
-	cmd_log_init(argc, argv, prefix, &rev);
+	memset(&opt, 0, sizeof(opt));
+	opt.def = "HEAD";
+	cmd_log_init(argc, argv, prefix, &rev, &opt);
 
 	/*
 	 * This means that we override whatever commit format the user gave
@@ -438,6 +447,7 @@ int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 int cmd_log(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info rev;
+	struct setup_revision_opt opt;
 
 	git_config(git_log_config, NULL);
 
@@ -446,7 +456,9 @@ int cmd_log(int argc, const char **argv, const char *prefix)
 
 	init_revisions(&rev, prefix);
 	rev.always_show_header = 1;
-	cmd_log_init(argc, argv, prefix, &rev);
+	memset(&opt, 0, sizeof(opt));
+	opt.def = "HEAD";
+	cmd_log_init(argc, argv, prefix, &rev, &opt);
 	return cmd_log_walk(&rev);
 }
 
@@ -887,6 +899,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	struct commit *commit;
 	struct commit **list = NULL;
 	struct rev_info rev;
+	struct setup_revision_opt s_r_opt;
 	int nr = 0, total, i;
 	int use_stdout = 0;
 	int start_number = -1;
@@ -964,8 +977,9 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	rev.combine_merges = 0;
 	rev.ignore_merges = 1;
 	DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
-
 	rev.subject_prefix = fmt_patch_subject_prefix;
+	memset(&s_r_opt, 0, sizeof(s_r_opt));
+	s_r_opt.def = "HEAD";
 
 	if (default_attach) {
 		rev.mime_boundary = default_attach;
@@ -1037,7 +1051,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	if (keep_subject && subject_prefix)
 		die ("--subject-prefix and -k are mutually exclusive.");
 
-	argc = setup_revisions(argc, argv, &rev, "HEAD");
+	argc = setup_revisions(argc, argv, &rev, &s_r_opt);
 	if (argc > 1)
 		die ("unrecognized argument: %s", argv[1]);
 

diff-lib.c

@@ -510,9 +510,12 @@ int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 int index_differs_from(const char *def, int diff_flags)
 {
 	struct rev_info rev;
+	struct setup_revision_opt opt;
 
 	init_revisions(&rev, NULL);
-	setup_revisions(0, NULL, &rev, def);
+	memset(&opt, 0, sizeof(opt));
+	opt.def = def;
+	setup_revisions(0, NULL, &rev, &opt);
 	DIFF_OPT_SET(&rev.diffopt, QUICK);
 	DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
 	rev.diffopt.flags |= diff_flags;

revision.c

@@ -1328,7 +1328,7 @@ static void append_prune_data(const char ***prune_data, const char **av)
  * Returns the number of arguments left that weren't recognized
  * (which are also moved to the head of the argument list)
  */
-int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
+int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
 {
 	int i, flags, left, seen_dashdash, read_from_stdin;
 	const char **prune_data = NULL;
@@ -1462,7 +1462,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 		revs->prune_data = get_pathspec(revs->prefix, prune_data);
 
 	if (revs->def == NULL)
-		revs->def = def;
+		revs->def = opt ? opt->def : NULL;
 	if (revs->show_merge)
 		prepare_show_merge(revs);
 	if (revs->def && !revs->pending.nr) {

revision.h

@@ -137,8 +137,12 @@ struct rev_info {
 typedef void (*show_early_output_fn_t)(struct rev_info *, struct commit_list *);
 extern volatile show_early_output_fn_t show_early_output;
 
+struct setup_revision_opt {
+	const char *def;
+};
+
 extern void init_revisions(struct rev_info *revs, const char *prefix);
-extern int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def);
+extern int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *);
 extern void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
 				 const struct option *options,
 				 const char * const usagestr[]);

wt-status.c

@@ -290,10 +290,13 @@ static void wt_status_collect_changes_worktree(struct wt_status *s)
 static void wt_status_collect_changes_index(struct wt_status *s)
 {
 	struct rev_info rev;
+	struct setup_revision_opt opt;
 
 	init_revisions(&rev, NULL);
-	setup_revisions(0, NULL, &rev,
-		s->is_initial ? EMPTY_TREE_SHA1_HEX : s->reference);
+	memset(&opt, 0, sizeof(opt));
+	opt.def = s->is_initial ? EMPTY_TREE_SHA1_HEX : s->reference;
+	setup_revisions(0, NULL, &rev, &opt);
+
 	rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 	rev.diffopt.format_callback = wt_status_collect_updated_cb;
 	rev.diffopt.format_callback_data = s;
@@ -512,11 +515,15 @@ static void wt_status_print_untracked(struct wt_status *s)
 static void wt_status_print_verbose(struct wt_status *s)
 {
 	struct rev_info rev;
+	struct setup_revision_opt opt;
 
 	init_revisions(&rev, NULL);
 	DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
-	setup_revisions(0, NULL, &rev,
-		s->is_initial ? EMPTY_TREE_SHA1_HEX : s->reference);
+
+	memset(&opt, 0, sizeof(opt));
+	opt.def = s->is_initial ? EMPTY_TREE_SHA1_HEX : s->reference;
+	setup_revisions(0, NULL, &rev, &opt);
+
 	rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
 	rev.diffopt.detect_rename = 1;
 	rev.diffopt.file = s->fp;