[RFC/WIP PATCH 1/4] disable complete ignorance of submodules for index <-> HEAD diff

[Heiko Voigt <hvoigt@hvoigt.net>]

If the value of ignore for submodules is set to "all" we would not show
whats actually committed during status or diff. This can result in the
user committing unexpected submodule references. Lets be nicer and always
show whats in the index.

Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net>
---
 builtin/diff.c            |  2 ++
 diff-lib.c                |  3 +++
 diff.h                    |  2 +-
 submodule.c               | 16 ++++++++++++++--
 submodule.h               |  1 +
 t/t4027-diff-submodule.sh | 12 +++++++++---
 t/t7508-status.sh         |  6 +++++-
 7 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/builtin/diff.c b/builtin/diff.c
index adb93a9..c47614d 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -162,6 +162,8 @@ static int builtin_diff_tree(struct rev_info *revs,
 	if (argc > 1)
 		usage(builtin_diff_usage);
 
+	enforce_no_complete_ignore_submodule(&revs->diffopt);
+
 	/*
 	 * We saw two trees, ent0 and ent1.  If ent1 is uninteresting,
 	 * swap them.
diff --git a/diff-lib.c b/diff-lib.c
index 346cac6..c5219cb 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -483,6 +483,9 @@ int run_diff_index(struct rev_info *revs, int cached)
 {
 	struct object_array_entry *ent;
 
+	if (cached)
+		enforce_no_complete_ignore_submodule(&revs->diffopt);
+
 	ent = revs->pending.objects;
 	if (diff_cache(revs, ent->item->sha1, ent->name, cached))
 		exit(128);
diff --git a/diff.h b/diff.h
index e342325..81561b3 100644
--- a/diff.h
+++ b/diff.h
@@ -64,7 +64,7 @@ typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data)
 #define DIFF_OPT_FIND_COPIES_HARDER  (1 <<  6)
 #define DIFF_OPT_FOLLOW_RENAMES      (1 <<  7)
 #define DIFF_OPT_RENAME_EMPTY        (1 <<  8)
-/* (1 <<  9) unused */
+#define DIFF_OPT_NO_IGNORE_SUBMODULE (1 <<  9)
 #define DIFF_OPT_HAS_CHANGES         (1 << 10)
 #define DIFF_OPT_QUICK               (1 << 11)
 #define DIFF_OPT_NO_INDEX            (1 << 12)
diff --git a/submodule.c b/submodule.c
index 1905d75..e0719b6 100644
--- a/submodule.c
+++ b/submodule.c
@@ -294,6 +294,16 @@ int parse_submodule_config_option(const char *var, const char *value)
 	return 0;
 }
 
+void enforce_no_complete_ignore_submodule(struct diff_options *diffopt)
+{
+	DIFF_OPT_SET(diffopt, NO_IGNORE_SUBMODULE);
+	if (DIFF_OPT_TST(diffopt, OVERRIDE_SUBMODULE_CONFIG) &&
+	    DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES)) {
+		DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
+		DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
+	}
+}
+
 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 				  const char *arg)
 {
@@ -301,9 +311,11 @@ void handle_ignore_submodules_arg(struct diff_options *diffopt,
 	DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 	DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
 
-	if (!strcmp(arg, "all"))
+	if (!strcmp(arg, "all")) {
+		if (DIFF_OPT_TST(diffopt, NO_IGNORE_SUBMODULE))
+			return;
 		DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
-	else if (!strcmp(arg, "untracked"))
+	} else if (!strcmp(arg, "untracked"))
 		DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 	else if (!strcmp(arg, "dirty"))
 		DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
diff --git a/submodule.h b/submodule.h
index 7beec48..2c8087e 100644
--- a/submodule.h
+++ b/submodule.h
@@ -20,6 +20,7 @@ void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 int submodule_config(const char *var, const char *value, void *cb);
 void gitmodules_config(void);
 int parse_submodule_config_option(const char *var, const char *value);
+void enforce_no_complete_ignore_submodule(struct diff_options *diffopt);
 void handle_ignore_submodules_arg(struct diff_options *diffopt, const char *);
 int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg);
 void show_submodule_summary(FILE *f, const char *path,
diff --git a/t/t4027-diff-submodule.sh b/t/t4027-diff-submodule.sh
index 518bf95..bd84ea7 100755
--- a/t/t4027-diff-submodule.sh
+++ b/t/t4027-diff-submodule.sh
@@ -258,7 +258,9 @@ test_expect_success 'git diff between submodule commits' '
 	expect_from_to >expect.body $subtip $subprev &&
 	test_cmp expect.body actual.body &&
 	git diff --ignore-submodules HEAD^..HEAD >actual &&
-	! test -s actual
+	sed -e "1,/^@@/d" actual >actual.body &&
+	expect_from_to >expect.body $subtip $subprev &&
+	test_cmp expect.body actual.body
 '
 
 test_expect_success 'git diff between submodule commits [.git/config]' '
@@ -274,7 +276,9 @@ test_expect_success 'git diff between submodule commits [.git/config]' '
 	test_cmp expect.body actual.body &&
 	git config submodule.subname.ignore all &&
 	git diff HEAD^..HEAD >actual &&
-	! test -s actual &&
+	sed -e "1,/^@@/d" actual >actual.body &&
+	expect_from_to >expect.body $subtip $subprev &&
+	test_cmp expect.body actual.body &&
 	git diff --ignore-submodules=dirty HEAD^..HEAD >actual &&
 	sed -e "1,/^@@/d" actual >actual.body &&
 	expect_from_to >expect.body $subtip $subprev &&
@@ -294,7 +298,9 @@ test_expect_success 'git diff between submodule commits [.gitmodules]' '
 	test_cmp expect.body actual.body &&
 	git config -f .gitmodules submodule.subname.ignore all &&
 	git diff HEAD^..HEAD >actual &&
-	! test -s actual &&
+	sed -e "1,/^@@/d" actual >actual.body &&
+	expect_from_to >expect.body $subtip $subprev &&
+	test_cmp expect.body actual.body &&
 	git config submodule.subname.ignore dirty &&
 	git config submodule.subname.path sub &&
 	git diff  HEAD^..HEAD >actual &&
diff --git a/t/t7508-status.sh b/t/t7508-status.sh
index c987b5e..977295f 100755
--- a/t/t7508-status.sh
+++ b/t/t7508-status.sh
@@ -1357,6 +1357,11 @@ test_expect_success "status (core.commentchar with two chars with submodule summ
 test_expect_success "--ignore-submodules=all suppresses submodule summary" '
 	cat > expect << EOF &&
 On branch master
+Changes to be committed:
+  (use "git reset HEAD <file>..." to unstage)
+
+	modified:   sm
+
 Changes not staged for commit:
   (use "git add <file>..." to update what will be committed)
   (use "git checkout -- <file>..." to discard changes in working directory)
@@ -1374,7 +1379,6 @@ Untracked files:
 	output
 	untracked
 
-no changes added to commit (use "git add" and/or "git commit -a")
 EOF
 	git status --ignore-submodules=all > output &&
 	test_i18ncmp expect output
-- 
1.8.5.1.43.gf00fb86