clone: make it possible to specify --tags

Option --no-tags was added in 0dab246 (clone: add a --no-tags option
to clone without tags, 2017-04-26). At the time there was no need to
support --tags as well, although there was some conversation about
it[1].

To simplify the code and to prepare for future commits, invert the flag
internally. Functionally there is no change, because the flag is
default-enabled passing `--tags` has no effect, so there's no need to
add tests for this.

[1]: https://lore.kernel.org/git/CAGZ79kbHuMpiavJ90kQLEL_AR0BEyArcZoEWAjPPhOFacN16YQ@mail.gmail.com/

Signed-off-by: Toon Claes <toon@iotcl.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: To1ne

Documentation/git-clone.txt

@@ -13,7 +13,7 @@ git clone [--template=<template-directory>]
 	  [-l] [-s] [--no-hardlinks] [-q] [-n] [--bare] [--mirror]
 	  [-o <name>] [-b <name>] [-u <upload-pack>] [--reference <repository>]
 	  [--dissociate] [--separate-git-dir <git-dir>]
-	  [--depth <depth>] [--[no-]single-branch] [--no-tags]
+	  [--depth <depth>] [--[no-]single-branch] [--[no-]tags]
 	  [--recurse-submodules[=<pathspec>]] [--[no-]shallow-submodules]
 	  [--[no-]remote-submodules] [--jobs <n>] [--sparse] [--[no-]reject-shallow]
 	  [--filter=<filter-spec>] [--also-filter-submodules]] [--] <repository>
@@ -273,12 +273,15 @@ corresponding `--mirror` and `--no-tags` options instead.
 	branch when `--single-branch` clone was made, no remote-tracking
 	branch is created.
 
-`--no-tags`::
-	Don't clone any tags, and set
-	`remote.<remote>.tagOpt=--no-tags` in the config, ensuring
-	that future `git pull` and `git fetch` operations won't follow
-	any tags. Subsequent explicit tag fetches will still work,
-	(see linkgit:git-fetch[1]).
+`--[no-]tags`::
+	Control whether or not tags will be cloned. When `--no-tags` is
+	given, the option will be become permanent by setting the
+	`remote.<remote>.tagOpt=--no-tags` configuration. This ensures that
+	future `git pull` and `git fetch` won't follow any tags. Subsequent
+	explicit tag fetches will still work (see linkgit:git-fetch[1]).
+
+	By default, tags are cloned and passing `--tags` is thus typically a
+	no-op, unless it cancels out a previous `--no-tags`.
 +
 Can be used in conjunction with `--single-branch` to clone and
 maintain a branch with no references other than a single cloned

builtin/clone.c

@@ -59,7 +59,7 @@
 
 static int option_no_checkout, option_bare, option_mirror, option_single_branch = -1;
 static int option_local = -1, option_no_hardlinks, option_shared;
-static int option_no_tags;
+static int option_tags = 1; /* default enabled */
 static int option_shallow_submodules;
 static int config_reject_shallow = -1;    /* unspecified */
 static char *remote_name = NULL;
@@ -470,7 +470,7 @@ static struct ref *wanted_peer_refs(const struct ref *refs,
 			get_fetch_map(refs, &refspec->items[i], &tail, 0);
 	}
 
-	if (!option_mirror && !option_single_branch && !option_no_tags)
+	if (!option_mirror && !option_single_branch && option_tags)
 		get_fetch_map(refs, &tag_refspec, &tail, 0);
 
 	refspec_item_clear(&tag_refspec);
@@ -562,7 +562,7 @@ static void update_remote_refs(const struct ref *refs,
 
 	if (refs) {
 		write_remote_refs(mapped_refs);
-		if (option_single_branch && !option_no_tags)
+		if (option_single_branch && option_tags)
 			write_followtags(refs, msg);
 	}
 
@@ -964,8 +964,8 @@ int cmd_clone(int argc,
 				N_("deepen history of shallow clone, excluding ref")),
 		OPT_BOOL(0, "single-branch", &option_single_branch,
 			 N_("clone only one branch, HEAD or --branch")),
-		OPT_BOOL(0, "no-tags", &option_no_tags,
-			 N_("don't clone any tags, and make later fetches not to follow them")),
+		OPT_BOOL(0, "tags", &option_tags,
+			 N_("clone tags, and make later fetches not to follow them")),
 		OPT_BOOL(0, "shallow-submodules", &option_shallow_submodules,
 			 N_("any cloned submodules will be shallow")),
 		OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
@@ -1296,7 +1296,7 @@ int cmd_clone(int argc,
 	git_config_set(key.buf, repo);
 	strbuf_reset(&key);
 
-	if (option_no_tags) {
+	if (!option_tags) {
 		strbuf_addf(&key, "remote.%s.tagOpt", remote_name);
 		git_config_set(key.buf, "--no-tags");
 		strbuf_reset(&key);
@@ -1389,7 +1389,7 @@ int cmd_clone(int argc,
 	if (option_branch)
 		expand_ref_prefix(&transport_ls_refs_options.ref_prefixes,
 				  option_branch);
-	if (!option_no_tags)
+	if (option_tags)
 		strvec_push(&transport_ls_refs_options.ref_prefixes,
 			    "refs/tags/");