wt-status.*: better advices for git status added

This patch provides new informative help messages in the display of
'git status' (at the top) during conflicts, rebase, am, bisect or
cherry-pick process.

The new messages are not shown when using options such as -s or
--porcelain. The messages about the current situation of the user are
always displayed but the advices on what the user needs to do in order
to resume a rebase/bisect/am/commit after resolving conflicts can be
hidden by setting advice.statushints to 'false' in the config file.

Thus, information about the updated advice.statushints key are added
in Documentation/config.txt.

Also, the test t7060-wt-status.sh is now working with the new help
messages. Tests about suggestions of "git rm" are also added.

Signed-off-by: Lucien Kong <Lucien.Kong@ensimag.imag.fr>
Signed-off-by: Valentin Duperray <Valentin.Duperray@ensimag.imag.fr>
Signed-off-by: Franck Jonas <Franck.Jonas@ensimag.imag.fr>
Signed-off-by: Thomas Nguy <Thomas.Nguy@ensimag.imag.fr>
Signed-off-by: Huynh Khoi Nguyen Nguyen <Huynh-Khoi-Nguyen.Nguyen@ensimag.imag.fr>
Signed-off-by: Matthieu Moy <Matthieu.Moy@grenoble-inp.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

4 files changed, 235 insertions, 3 deletions

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 915cb5a547..ccce4f6697 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -159,9 +159,10 @@ advice.*::
 		specified a refspec that isn't your current branch) and
 		it resulted in a non-fast-forward error.
 	statusHints::
-		Directions on how to stage/unstage/add shown in the
-		output of linkgit:git-status[1] and the template shown
-		when writing commit messages.
+		Show directions on how to proceed from the current
+		state in the output of linkgit:git-status[1] and in
+		the template shown when writing commit messages in
+		linkgit:git-commit[1].
 	commitBeforeMerge::
 		Advice shown when linkgit:git-merge[1] refuses to
 		merge to avoid overwriting local changes.
diff --git a/t/t7060-wtstatus.sh b/t/t7060-wtstatus.sh
index b8cb4906aa..e8c3690dac 100755
--- a/t/t7060-wtstatus.sh
+++ b/t/t7060-wtstatus.sh
@@ -30,6 +30,9 @@ test_expect_success 'Report new path with conflict' '
 
 cat >expect <<EOF
 # On branch side
+# You have unmerged paths.
+#   (fix conflicts and run "git commit")
+#
 # Unmerged paths:
 #   (use "git add/rm <file>..." as appropriate to mark resolution)
 #
@@ -118,4 +121,65 @@ test_expect_success 'git diff-index --cached -C shows 2 copies + 1 unmerged' '
 	test_cmp expected actual
 '
 
+
+test_expect_success 'status when conflicts with add and rm advice (deleted by them)' '
+	git reset --hard &&
+	git checkout master &&
+	test_commit init main.txt init &&
+	git checkout -b second_branch &&
+	git rm main.txt &&
+	git commit -m "main.txt deleted on second_branch" &&
+	test_commit second conflict.txt second &&
+	git checkout master &&
+	test_commit on_second main.txt on_second &&
+	test_commit master conflict.txt master &&
+	test_must_fail git merge second_branch &&
+	cat >expected <<-\EOF &&
+	# On branch master
+	# You have unmerged paths.
+	#   (fix conflicts and run "git commit")
+	#
+	# Unmerged paths:
+	#   (use "git add/rm <file>..." as appropriate to mark resolution)
+	#
+	#	both added:         conflict.txt
+	#	deleted by them:    main.txt
+	#
+	no changes added to commit (use "git add" and/or "git commit -a")
+	EOF
+	git status --untracked-files=no >actual &&
+	test_i18ncmp expected actual
+'
+
+
+test_expect_success 'status when conflicts with add and rm advice (both deleted)' '
+	git reset --hard &&
+	git checkout -b conflict &&
+	test_commit one main.txt one &&
+	git branch conflict_second &&
+	git mv main.txt sub_master.txt &&
+	git commit -m "main.txt renamed in sub_master.txt" &&
+	git checkout conflict_second &&
+	git mv main.txt sub_second.txt &&
+	git commit -m "main.txt renamed in sub_second.txt" &&
+	test_must_fail git merge conflict &&
+	cat >expected <<-\EOF &&
+	# On branch conflict_second
+	# You have unmerged paths.
+	#   (fix conflicts and run "git commit")
+	#
+	# Unmerged paths:
+	#   (use "git add/rm <file>..." as appropriate to mark resolution)
+	#
+	#	both deleted:       main.txt
+	#	added by them:      sub_master.txt
+	#	added by us:        sub_second.txt
+	#
+	no changes added to commit (use "git add" and/or "git commit -a")
+	EOF
+	git status --untracked-files=no >actual &&
+	test_i18ncmp expected actual
+'
+
+
 test_done
diff --git a/wt-status.c b/wt-status.c
index dd6d8c4106..e404f2d9ec 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -23,6 +23,7 @@ static char default_wt_status_colors[][COLOR_MAXLEN] = {
 	GIT_COLOR_GREEN,  /* WT_STATUS_LOCAL_BRANCH */
 	GIT_COLOR_RED,    /* WT_STATUS_REMOTE_BRANCH */
 	GIT_COLOR_NIL,    /* WT_STATUS_ONBRANCH */
+	GIT_COLOR_NORMAL, /* WT_STATUS_IN_PROGRESS */
 };
 
 static const char *color(int slot, struct wt_status *s)
@@ -728,6 +729,160 @@ static void wt_status_print_tracking(struct wt_status *s)
 	color_fprintf_ln(s->fp, color(WT_STATUS_HEADER, s), "#");
 }
 
+static int has_unmerged(struct wt_status *s)
+{
+	int i;
+
+	for (i = 0; i < s->change.nr; i++) {
+		struct wt_status_change_data *d;
+		d = s->change.items[i].util;
+		if (d->stagemask)
+			return 1;
+	}
+	return 0;
+}
+
+static void show_merge_in_progress(struct wt_status *s,
+				struct wt_status_state *state,
+				const char *color)
+{
+	if (has_unmerged(s)) {
+		status_printf_ln(s, color, _("You have unmerged paths."));
+		if (advice_status_hints)
+			status_printf_ln(s, color,
+				_("  (fix conflicts and run \"git commit\")"));
+	} else {
+		status_printf_ln(s, color,
+			_("All conflicts fixed but you are still merging."));
+		if (advice_status_hints)
+			status_printf_ln(s, color,
+				_("  (use \"git commit\" to conclude merge)"));
+	}
+	wt_status_print_trailer(s);
+}
+
+static void show_am_in_progress(struct wt_status *s,
+				struct wt_status_state *state,
+				const char *color)
+{
+	status_printf_ln(s, color,
+		_("You are in the middle of an am session."));
+	if (state->am_empty_patch)
+		status_printf_ln(s, color,
+			_("The current patch is empty."));
+	if (advice_status_hints) {
+		if (!state->am_empty_patch)
+			status_printf_ln(s, color,
+				_("  (fix conflicts and then run \"git am --resolved\")"));
+		status_printf_ln(s, color,
+			_("  (use \"git am --skip\" to skip this patch)"));
+		status_printf_ln(s, color,
+			_("  (use \"git am --abort\" to restore the original branch)"));
+	}
+	wt_status_print_trailer(s);
+}
+
+static void show_rebase_in_progress(struct wt_status *s,
+				struct wt_status_state *state,
+				const char *color)
+{
+	struct stat st;
+
+	if (has_unmerged(s)) {
+		status_printf_ln(s, color, _("You are currently rebasing."));
+		if (advice_status_hints) {
+			status_printf_ln(s, color,
+				_("  (fix conflicts and then run \"git rebase --continue\")"));
+			status_printf_ln(s, color,
+				_("  (use \"git rebase --skip\" to skip this patch)"));
+			status_printf_ln(s, color,
+				_("  (use \"git rebase --abort\" to check out the original branch)"));
+		}
+	} else if (state->rebase_in_progress || !stat(git_path("MERGE_MSG"), &st)) {
+		status_printf_ln(s, color, _("You are currently rebasing."));
+		if (advice_status_hints)
+			status_printf_ln(s, color,
+				_("  (all conflicts fixed: run \"git rebase --continue\")"));
+	} else {
+		status_printf_ln(s, color, _("You are currently editing a commit during a rebase."));
+		if (advice_status_hints && !s->amend) {
+			status_printf_ln(s, color,
+				_("  (use \"git commit --amend\" to amend the current commit)"));
+			status_printf_ln(s, color,
+				_("  (use \"git rebase --continue\" once you are satisfied with your changes)"));
+		}
+	}
+	wt_status_print_trailer(s);
+}
+
+static void show_cherry_pick_in_progress(struct wt_status *s,
+					struct wt_status_state *state,
+					const char *color)
+{
+	status_printf_ln(s, color, _("You are currently cherry-picking."));
+	if (advice_status_hints) {
+		if (has_unmerged(s))
+			status_printf_ln(s, color,
+				_("  (fix conflicts and run \"git commit\")"));
+		else
+			status_printf_ln(s, color,
+				_("  (all conflicts fixed: run \"git commit\")"));
+	}
+	wt_status_print_trailer(s);
+}
+
+static void show_bisect_in_progress(struct wt_status *s,
+				struct wt_status_state *state,
+				const char *color)
+{
+	status_printf_ln(s, color, _("You are currently bisecting."));
+	if (advice_status_hints)
+		status_printf_ln(s, color,
+			_("  (use \"git bisect reset\" to get back to the original branch)"));
+	wt_status_print_trailer(s);
+}
+
+static void wt_status_print_state(struct wt_status *s)
+{
+	const char *state_color = color(WT_STATUS_IN_PROGRESS, s);
+	struct wt_status_state state;
+	struct stat st;
+
+	memset(&state, 0, sizeof(state));
+
+	if (!stat(git_path("MERGE_HEAD"), &st)) {
+		state.merge_in_progress = 1;
+	} else if (!stat(git_path("rebase-apply"), &st)) {
+		if (!stat(git_path("rebase-apply/applying"), &st)) {
+			state.am_in_progress = 1;
+			if (!stat(git_path("rebase-apply/patch"), &st) && !st.st_size)
+				state.am_empty_patch = 1;
+		} else {
+			state.rebase_in_progress = 1;
+		}
+	} else if (!stat(git_path("rebase-merge"), &st)) {
+		if (!stat(git_path("rebase-merge/interactive"), &st))
+			state.rebase_interactive_in_progress = 1;
+		else
+			state.rebase_in_progress = 1;
+	} else if (!stat(git_path("CHERRY_PICK_HEAD"), &st)) {
+		state.cherry_pick_in_progress = 1;
+	}
+	if (!stat(git_path("BISECT_LOG"), &st))
+		state.bisect_in_progress = 1;
+
+	if (state.merge_in_progress)
+		show_merge_in_progress(s, &state, state_color);
+	else if (state.am_in_progress)
+		show_am_in_progress(s, &state, state_color);
+	else if (state.rebase_in_progress || state.rebase_interactive_in_progress)
+		show_rebase_in_progress(s, &state, state_color);
+	else if (state.cherry_pick_in_progress)
+		show_cherry_pick_in_progress(s, &state, state_color);
+	if (state.bisect_in_progress)
+		show_bisect_in_progress(s, &state, state_color);
+}
+
 void wt_status_print(struct wt_status *s)
 {
 	const char *branch_color = color(WT_STATUS_ONBRANCH, s);
@@ -750,6 +905,7 @@ void wt_status_print(struct wt_status *s)
 			wt_status_print_tracking(s);
 	}
 
+	wt_status_print_state(s);
 	if (s->is_initial) {
 		status_printf_ln(s, color(WT_STATUS_HEADER, s), "");
 		status_printf_ln(s, color(WT_STATUS_HEADER, s), _("Initial commit"));
diff --git a/wt-status.h b/wt-status.h
index 14aa9f7e13..c1066a0ec6 100644
--- a/wt-status.h
+++ b/wt-status.h
@@ -15,6 +15,7 @@ enum color_wt_status {
 	WT_STATUS_LOCAL_BRANCH,
 	WT_STATUS_REMOTE_BRANCH,
 	WT_STATUS_ONBRANCH,
+	WT_STATUS_IN_PROGRESS,
 	WT_STATUS_MAXSLOT
 };
 
@@ -71,6 +72,16 @@ struct wt_status {
 	struct string_list ignored;
 };
 
+struct wt_status_state {
+	int merge_in_progress;
+	int am_in_progress;
+	int am_empty_patch;
+	int rebase_in_progress;
+	int rebase_interactive_in_progress;
+	int cherry_pick_in_progress;
+	int bisect_in_progress;
+};
+
 void wt_status_prepare(struct wt_status *s);
 void wt_status_print(struct wt_status *s);
 void wt_status_collect(struct wt_status *s);