[PATCH 7/8] diff.h: extend "flags" field to 64 bits because we're out of bits

[PATCH 7/8] diff.h: extend "flags" field to 64 bits because we're out of bits

[Nguyễn Thái Ngọc Duy]

I renamed both "flags" and "touched_flags" fields while making this
patch to make sure I was aware of how these flags were manipulated
(besides DIFF_OPT* macros). So hopefully I didn't miss anything.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 Resend to the right recipients. I screwed send-email up..

 builtin/commit.c | 2 +-
 diff-lib.c       | 4 ++--
 diff.c           | 2 +-
 diff.h           | 8 +++++---
 4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/builtin/commit.c b/builtin/commit.c
index 4cbd5ff..95f7296 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -895,7 +895,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 			 * submodules which were manually staged, which would
 			 * be really confusing.
 			 */
-			int diff_flags = DIFF_OPT_OVERRIDE_SUBMODULE_CONFIG;
+			diff_flags_t diff_flags = DIFF_OPT_OVERRIDE_SUBMODULE_CONFIG;
 			if (ignore_submodule_arg &&
 			    !strcmp(ignore_submodule_arg, "all"))
 				diff_flags |= DIFF_OPT_IGNORE_SUBMODULES;
diff --git a/diff-lib.c b/diff-lib.c
index 241a843..ae09034 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -71,7 +71,7 @@ static int match_stat_with_submodule(struct diff_options *diffopt,
 {
 	int changed = ce_match_stat(ce, st, ce_option);
 	if (S_ISGITLINK(ce->ce_mode)) {
-		unsigned orig_flags = diffopt->flags;
+		diff_flags_t orig_flags = diffopt->flags;
 		if (!DIFF_OPT_TST(diffopt, OVERRIDE_SUBMODULE_CONFIG))
 			set_diffopt_flags_from_submodule_config(diffopt, ce->name);
 		if (DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES))
@@ -516,7 +516,7 @@ int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 	return 0;
 }
 
-int index_differs_from(const char *def, int diff_flags)
+int index_differs_from(const char *def, diff_flags_t diff_flags)
 {
 	struct rev_info rev;
 	struct setup_revision_opt opt;
diff --git a/diff.c b/diff.c
index 7deac90..2485870 100644
--- a/diff.c
+++ b/diff.c
@@ -4912,7 +4912,7 @@ int diff_can_quit_early(struct diff_options *opt)
 static int is_submodule_ignored(const char *path, struct diff_options *options)
 {
 	int ignored = 0;
-	unsigned orig_flags = options->flags;
+	diff_flags_t orig_flags = options->flags;
 	if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
 		set_diffopt_flags_from_submodule_config(options, path);
 	if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
diff --git a/diff.h b/diff.h
index f7208ad..4241aa5 100644
--- a/diff.h
+++ b/diff.h
@@ -110,13 +110,15 @@ enum diff_words_type {
 	DIFF_WORDS_COLOR
 };
 
+typedef uint64_t diff_flags_t;
+
 struct diff_options {
 	const char *orderfile;
 	const char *pickaxe;
 	const char *single_follow;
 	const char *a_prefix, *b_prefix;
-	unsigned flags;
-	unsigned touched_flags;
+	diff_flags_t flags;
+	diff_flags_t touched_flags;
 
 	/* diff-filter bits */
 	unsigned int filter;
@@ -347,7 +349,7 @@ extern int diff_result_code(struct diff_options *, int);
 
 extern void diff_no_index(struct rev_info *, int, const char **, const char *);
 
-extern int index_differs_from(const char *def, int diff_flags);
+extern int index_differs_from(const char *def, diff_flags_t diff_flags);
 
 extern size_t fill_textconv(struct userdiff_driver *driver,
 			    struct diff_filespec *df,
-- 
2.3.0.rc1.137.g477eb31

[PATCH 8/8] Resurrect "diff-lib.c: adjust position of i-t-a entries in diff"

[Nguyễn Thái Ngọc Duy]

The original commit d95d728aba06a34394d15466045cbdabdada58a2 was
reverted in commit 78cc1a540ba127b13f2f3fd531777b57f3a9cd46 because we
were (and still are) not ready for a new world order. A lot more
investigation must be done to see what is impacted. See the 78cc1a5 for
details.

This patch takes a smaller and safer step. The new behavior is
controlled by SHIFT_INTENT_TO_ADD flag. We can gradually move more diff
users to the new behavior after we are sure it's safe to do so. This
flag is exposed to outside as "--shift-ita".

"git status" sets this flag unconditionally to display i-t-a entries
correctly. See d95d728 for details about "git status" and i-t-a entries.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 Documentation/diff-options.txt |  6 ++++++
 diff-lib.c                     | 14 ++++++++++++++
 diff.c                         |  2 ++
 diff.h                         |  1 +
 t/t2203-add-intent.sh          | 20 ++++++++++++++++++--
 wt-status.c                    |  2 ++
 6 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index d56ca90..b69db29 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -556,5 +556,11 @@ endif::git-format-patch[]
 --no-prefix::
 	Do not show any source or destination prefix.
 
+--shift-ita::
+	By default entries added by "git add -N" appear as an existing
+	empty file in "git diff" and a new file in "git diff --cached".
+	This option makes the entry appear as a new file in "git diff"
+	and non-existent in "git diff --cached".
+
 For more detailed explanation on these common options, see also
 linkgit:gitdiffcore[7].
diff --git a/diff-lib.c b/diff-lib.c
index ae09034..2546f5a 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -212,6 +212,12 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 					       ce->sha1, !is_null_sha1(ce->sha1),
 					       ce->name, 0);
 				continue;
+			} else if (DIFF_OPT_TST(&revs->diffopt, SHIFT_INTENT_TO_ADD) &&
+				   ce_intent_to_add(ce)) {
+				diff_addremove(&revs->diffopt, '+', ce->ce_mode,
+					       EMPTY_BLOB_SHA1_BIN, 0,
+					       ce->name, 0);
+				continue;
 			}
 
 			changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
@@ -376,6 +382,14 @@ static void do_oneway_diff(struct unpack_trees_options *o,
 	struct rev_info *revs = o->unpack_data;
 	int match_missing, cached;
 
+	/* i-t-a entries do not actually exist in the index */
+	if (DIFF_OPT_TST(&revs->diffopt, SHIFT_INTENT_TO_ADD) &&
+	    idx && ce_intent_to_add(idx)) {
+		idx = NULL;
+		if (!tree)
+			return;	/* nothing to diff.. */
+	}
+
 	/* if the entry is not checked out, don't examine work tree */
 	cached = o->index_only ||
 		(idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
diff --git a/diff.c b/diff.c
index 2485870..e554cad 100644
--- a/diff.c
+++ b/diff.c
@@ -3890,6 +3890,8 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		return parse_submodule_opt(options, arg);
 	else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
 		return parse_ws_error_highlight(options, arg);
+	else if (!strcmp(arg, "--shift-ita"))
+		DIFF_OPT_SET(options, SHIFT_INTENT_TO_ADD);
 
 	/* misc options */
 	else if (!strcmp(arg, "-z"))
diff --git a/diff.h b/diff.h
index 4241aa5..68a4400 100644
--- a/diff.h
+++ b/diff.h
@@ -92,6 +92,7 @@ typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data)
 #define DIFF_OPT_FUNCCONTEXT         (1 << 29)
 #define DIFF_OPT_PICKAXE_IGNORE_CASE (1 << 30)
 #define DIFF_OPT_DEFAULT_FOLLOW_RENAMES (1 << 31)
+#define DIFF_OPT_SHIFT_INTENT_TO_ADD (1ULL << 32)
 
 #define DIFF_OPT_TST(opts, flag)    ((opts)->flags & DIFF_OPT_##flag)
 #define DIFF_OPT_TOUCHED(opts, flag)    ((opts)->touched_flags & DIFF_OPT_##flag)
diff --git a/t/t2203-add-intent.sh b/t/t2203-add-intent.sh
index d0f36a4..7c90eee 100755
--- a/t/t2203-add-intent.sh
+++ b/t/t2203-add-intent.sh
@@ -5,10 +5,24 @@ test_description='Intent to add'
 . ./test-lib.sh
 
 test_expect_success 'intent to add' '
+	test_commit 1 &&
+	git rm 1.t &&
+	echo hello >1.t &&
 	echo hello >file &&
 	echo hello >elif &&
 	git add -N file &&
-	git add elif
+	git add elif &&
+	git add -N 1.t
+'
+
+test_expect_success 'git status' '
+	git status --porcelain | grep -v actual >actual &&
+	cat >expect <<-\EOF &&
+	DA 1.t
+	A  elif
+	 A file
+	EOF
+	test_cmp expect actual
 '
 
 test_expect_success 'check result of "add -N"' '
@@ -43,7 +57,9 @@ test_expect_success 'i-t-a entry is simply ignored' '
 	git add -N nitfol &&
 	git commit -m second &&
 	test $(git ls-tree HEAD -- nitfol | wc -l) = 0 &&
-	test $(git diff --name-only HEAD -- nitfol | wc -l) = 1
+	test $(git diff --name-only HEAD -- nitfol | wc -l) = 1 &&
+	test $(git diff --name-only --shift-ita HEAD -- nitfol | wc -l) = 0 &&
+	test $(git diff --name-only --shift-ita -- nitfol | wc -l) = 1
 '
 
 test_expect_success 'can commit with an unrelated i-t-a entry in index' '
diff --git a/wt-status.c b/wt-status.c
index 717fd48..534d4ad 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -497,6 +497,7 @@ static void wt_status_collect_changes_worktree(struct wt_status *s)
 	setup_revisions(0, NULL, &rev, NULL);
 	rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 	DIFF_OPT_SET(&rev.diffopt, DIRTY_SUBMODULES);
+	DIFF_OPT_SET(&rev.diffopt, SHIFT_INTENT_TO_ADD);
 	if (!s->show_untracked_files)
 		DIFF_OPT_SET(&rev.diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 	if (s->ignore_submodule_arg) {
@@ -520,6 +521,7 @@ static void wt_status_collect_changes_index(struct wt_status *s)
 	setup_revisions(0, NULL, &rev, &opt);
 
 	DIFF_OPT_SET(&rev.diffopt, OVERRIDE_SUBMODULE_CONFIG);
+	DIFF_OPT_SET(&rev.diffopt, SHIFT_INTENT_TO_ADD);
 	if (s->ignore_submodule_arg) {
 		handle_ignore_submodules_arg(&rev.diffopt, s->ignore_submodule_arg);
 	} else {
-- 
2.3.0.rc1.137.g477eb31