[PATCHv2 4/4] builtin/reset: add --recurse-submodules switch

[Stefan Beller <sbeller@google.com>]

git-reset is yet another working tree manipulator, which should
be taught about submodules.

One use case of "git-reset" is to reset to a known good state,
and dropping commits that did not work as expected.
In that case one of the expected outcomes from a hard reset
would be to have broken submodules reset to a known good
state as well.  A test for this was added in a prior patch.

Signed-off-by: Stefan Beller <sbeller@google.com>
---
 builtin/reset.c            | 30 ++++++++++++++++++++++++++++++
 t/t7112-reset-submodule.sh |  8 ++++++++
 2 files changed, 38 insertions(+)

diff --git a/builtin/reset.c b/builtin/reset.c
index fc3b906c47..5ce27fcaed 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -21,6 +21,27 @@
 #include "parse-options.h"
 #include "unpack-trees.h"
 #include "cache-tree.h"
+#include "submodule.h"
+#include "submodule-config.h"
+
+static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
+
+static int option_parse_recurse_submodules(const struct option *opt,
+					   const char *arg, int unset)
+{
+	if (unset) {
+		recurse_submodules = RECURSE_SUBMODULES_OFF;
+		return 0;
+	}
+	if (arg)
+		recurse_submodules =
+			parse_update_recurse_submodules_arg(opt->long_name,
+							    arg);
+	else
+		recurse_submodules = RECURSE_SUBMODULES_ON;
+
+	return 0;
+}
 
 static const char * const git_reset_usage[] = {
 	N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
@@ -283,6 +304,9 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 				N_("reset HEAD, index and working tree"), MERGE),
 		OPT_SET_INT(0, "keep", &reset_type,
 				N_("reset HEAD but keep local changes"), KEEP),
+		{ OPTION_CALLBACK, 0, "recurse-submodules", &recurse_submodules,
+			    "reset", "control recursive updating of submodules",
+			    PARSE_OPT_OPTARG, option_parse_recurse_submodules },
 		OPT_BOOL('p', "patch", &patch_mode, N_("select hunks interactively")),
 		OPT_BOOL('N', "intent-to-add", &intent_to_add,
 				N_("record only the fact that removed paths will be added later")),
@@ -295,6 +319,12 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 						PARSE_OPT_KEEP_DASHDASH);
 	parse_args(&pathspec, argv, prefix, patch_mode, &rev);
 
+	if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT) {
+		gitmodules_config();
+		git_config(submodule_config, NULL);
+		set_config_update_recurse_submodules(RECURSE_SUBMODULES_ON);
+	}
+
 	unborn = !strcmp(rev, "HEAD") && get_sha1("HEAD", oid.hash);
 	if (unborn) {
 		/* reset on unborn branch: treat as reset to empty tree */
diff --git a/t/t7112-reset-submodule.sh b/t/t7112-reset-submodule.sh
index 2eda6adeb1..f86ccdf215 100755
--- a/t/t7112-reset-submodule.sh
+++ b/t/t7112-reset-submodule.sh
@@ -5,6 +5,14 @@ test_description='reset can handle submodules'
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-submodule-update.sh
 
+KNOWN_FAILURE_SUBMODULE_RECURSIVE_NESTED=1
+KNOWN_FAILURE_DIRECTORY_SUBMODULE_CONFLICTS=1
+KNOWN_FAILURE_SUBMODULE_OVERWRITE_IGNORED_UNTRACKED=1
+
+test_submodule_switch_recursing "git reset --recurse-submodules --keep"
+
+test_submodule_forced_switch_recursing "git reset --hard --recurse-submodules"
+
 test_submodule_switch "git reset --keep"
 
 test_submodule_switch "git reset --merge"
-- 
2.12.2.642.g1b8cc69eee.dirty