clone: pass --progress decision to recursive submodules

When cloning with "--recursive", we'd generally expect
submodules to show progress reports if the main clone did,
too.

In older versions of git, this mostly worked out of the
box. Since we show progress by default when stderr is a tty,
and since the child clones inherit the parent stderr, then
both processes would come to the same decision by default.
If the parent clone was asked for "--quiet", we passed down
"--quiet" to the child. However, if stderr was not a tty and
the user specified "--progress", we did not propagate this
to the child.

That's a minor bug, but things got much worse when we
switched recently to submodule--helper's update_clone
command. With that change, the stderr of the child clones
are always connected to a pipe, and we never output
progress at all.

This patch teaches git-submodule and git-submodule--helper
how to pass down an explicit "--progress" flag when cloning.
The clone command then decides to propagate that flag based
on the cloning decision made earlier (which takes into
account isatty(2) of the parent process, existing --progress
or --quiet flags, etc). Since the child processes always run
without a tty on stderr, we don't have to worry about
passing an explicit "--no-progress"; it's the default for
them.

This fixes the recent loss of progress during recursive
clones. And as a bonus, it makes:

  git clone --recursive --progress ... 2>&1 | cat

work by triggering progress explicitly in the children.

Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/clone.c

@@ -670,7 +670,7 @@ static void update_head(const struct ref *our, const struct ref *remote,
 	}
 }
 
-static int checkout(void)
+static int checkout(int submodule_progress)
 {
 	unsigned char sha1[20];
 	char *head;
@@ -734,6 +734,9 @@ static int checkout(void)
 		if (max_jobs != -1)
 			argv_array_pushf(&args, "--jobs=%d", max_jobs);
 
+		if (submodule_progress)
+			argv_array_push(&args, "--progress");
+
 		err = run_command_v_opt(args.argv, RUN_GIT_CMD);
 		argv_array_clear(&args);
 	}
@@ -841,6 +844,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	const char *src_ref_prefix = "refs/heads/";
 	struct remote *remote;
 	int err = 0, complete_refs_before_fetch = 1;
+	int submodule_progress;
 
 	struct refspec *refspec;
 	const char *fetch_pattern;
@@ -1099,6 +1103,14 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 	update_head(our_head_points_at, remote_head, reflog_msg.buf);
 
+	/*
+	 * We want to show progress for recursive submodule clones iff
+	 * we did so for the main clone. But only the transport knows
+	 * the final decision for this flag, so we need to rescue the value
+	 * before we free the transport.
+	 */
+	submodule_progress = transport->progress;
+
 	transport_unlock_pack(transport);
 	transport_disconnect(transport);
 
@@ -1108,7 +1120,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	}
 
 	junk_mode = JUNK_LEAVE_REPO;
-	err = checkout();
+	err = checkout(submodule_progress);
 
 	strbuf_release(&reflog_msg);
 	strbuf_release(&branch_top);

builtin/submodule--helper.c

@@ -442,14 +442,17 @@ static int module_name(int argc, const char **argv, const char *prefix)
 }
 
 static int clone_submodule(const char *path, const char *gitdir, const char *url,
-			   const char *depth, struct string_list *reference, int quiet)
+			   const char *depth, struct string_list *reference,
+			   int quiet, int progress)
 {
 	struct child_process cp = CHILD_PROCESS_INIT;
 
 	argv_array_push(&cp.args, "clone");
 	argv_array_push(&cp.args, "--no-checkout");
 	if (quiet)
 		argv_array_push(&cp.args, "--quiet");
+	if (progress)
+		argv_array_push(&cp.args, "--progress");
 	if (depth && *depth)
 		argv_array_pushl(&cp.args, "--depth", depth, NULL);
 	if (reference->nr) {
@@ -574,6 +577,7 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 {
 	const char *name = NULL, *url = NULL, *depth = NULL;
 	int quiet = 0;
+	int progress = 0;
 	FILE *submodule_dot_git;
 	char *p, *path = NULL, *sm_gitdir;
 	struct strbuf rel_path = STRBUF_INIT;
@@ -600,6 +604,8 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 			   N_("string"),
 			   N_("depth for shallow clones")),
 		OPT__QUIET(&quiet, "Suppress output for cloning a submodule"),
+		OPT_BOOL(0, "progress", &progress,
+			   N_("force cloning progress")),
 		OPT_END()
 	};
 
@@ -633,7 +639,8 @@ static int module_clone(int argc, const char **argv, const char *prefix)
 
 		prepare_possible_alternates(name, &reference);
 
-		if (clone_submodule(path, sm_gitdir, url, depth, &reference, quiet))
+		if (clone_submodule(path, sm_gitdir, url, depth, &reference,
+				    quiet, progress))
 			die(_("clone of '%s' into submodule path '%s' failed"),
 			    url, path);
 	} else {
@@ -683,6 +690,7 @@ struct submodule_update_clone {
 	struct submodule_update_strategy update;
 
 	/* configuration parameters which are passed on to the children */
+	int progress;
 	int quiet;
 	int recommend_shallow;
 	struct string_list references;
@@ -701,7 +709,7 @@ struct submodule_update_clone {
 	int failed_clones_nr, failed_clones_alloc;
 };
 #define SUBMODULE_UPDATE_CLONE_INIT {0, MODULE_LIST_INIT, 0, \
-	SUBMODULE_UPDATE_STRATEGY_INIT, 0, -1, STRING_LIST_INIT_DUP, \
+	SUBMODULE_UPDATE_STRATEGY_INIT, 0, 0, -1, STRING_LIST_INIT_DUP, \
 	NULL, NULL, NULL, \
 	STRING_LIST_INIT_DUP, 0, NULL, 0, 0}
 
@@ -803,6 +811,8 @@ static int prepare_to_clone_next_submodule(const struct cache_entry *ce,
 	child->err = -1;
 	argv_array_push(&child->args, "submodule--helper");
 	argv_array_push(&child->args, "clone");
+	if (suc->progress)
+		argv_array_push(&child->args, "--progress");
 	if (suc->quiet)
 		argv_array_push(&child->args, "--quiet");
 	if (suc->prefix)
@@ -949,6 +959,8 @@ static int update_clone(int argc, const char **argv, const char *prefix)
 		OPT_BOOL(0, "recommend-shallow", &suc.recommend_shallow,
 			    N_("whether the initial clone should follow the shallow recommendation")),
 		OPT__QUIET(&suc.quiet, N_("don't print cloning progress")),
+		OPT_BOOL(0, "progress", &suc.progress,
+			    N_("force cloning progress")),
 		OPT_END()
 	};
 

git-submodule.sh

@@ -44,6 +44,7 @@ update=
 prefix=
 custom_name=
 depth=
+progress=
 
 die_if_unmatched ()
 {
@@ -498,6 +499,9 @@ cmd_update()
 		-q|--quiet)
 			GIT_QUIET=1
 			;;
+		--progress)
+			progress="--progress"
+			;;
 		-i|--init)
 			init=1
 			;;
@@ -573,6 +577,7 @@ cmd_update()
 
 	{
 	git submodule--helper update-clone ${GIT_QUIET:+--quiet} \
+		${progress:+"$progress"} \
 		${wt_prefix:+--prefix "$wt_prefix"} \
 		${prefix:+--recursive-prefix "$prefix"} \
 		${update:+--update "$update"} \