Merge branch 'en/sparse-status'

"git status" learned to report the status of sparse checkout.

* en/sparse-status:
  git-prompt: include sparsity state as well
  git-prompt: document how in-progress operations affect the prompt
  wt-status: show sparse checkout status as well

3 files changed, 67 insertions, 2 deletions

diff --git a/contrib/completion/git-prompt.sh b/contrib/completion/git-prompt.sh
index 014cd7c..e6cd546 100644
--- a/contrib/completion/git-prompt.sh
+++ b/contrib/completion/git-prompt.sh
@@ -70,6 +70,15 @@
 # state symbols by setting GIT_PS1_STATESEPARATOR. The default separator
 # is SP.
 #
+# When there is an in-progress operation such as a merge, rebase,
+# revert, cherry-pick, or bisect, the prompt will include information
+# related to the operation, often in the form "|<OPERATION-NAME>".
+#
+# When the repository has a sparse-checkout, a notification of the form
+# "|SPARSE" will be included in the prompt.  This can be shortened to a
+# single '?' character by setting GIT_PS1_COMPRESSSPARSESTATE, or omitted
+# by setting GIT_PS1_OMITSPARSESTATE.
+#
 # By default, __git_ps1 will compare HEAD to your SVN upstream if it can
 # find one, or @{upstream} otherwise.  Once you have set
 # GIT_PS1_SHOWUPSTREAM, you can override it on a per-repository basis by
@@ -421,6 +430,13 @@ __git_ps1 ()
 		return $exit
 	fi
 
+	local sparse=""
+	if [ -z "${GIT_PS1_COMPRESSSPARSESTATE}" ] &&
+	   [ -z "${GIT_PS1_OMITSPARSESTATE}" ] &&
+	   [ "$(git config --bool core.sparseCheckout)" == "true" ]; then
+		sparse="|SPARSE"
+	fi
+
 	local r=""
 	local b=""
 	local step=""
@@ -492,6 +508,7 @@ __git_ps1 ()
 	local i=""
 	local s=""
 	local u=""
+	local h=""
 	local c=""
 	local p=""
 
@@ -524,6 +541,11 @@ __git_ps1 ()
 			u="%${ZSH_VERSION+%}"
 		fi
 
+		if [ -n "${GIT_PS1_COMPRESSSPARSESTATE}" ] &&
+		   [ "$(git config --bool core.sparseCheckout)" == "true" ]; then
+			h="?"
+		fi
+
 		if [ -n "${GIT_PS1_SHOWUPSTREAM-}" ]; then
 			__git_ps1_show_upstream
 		fi
@@ -542,8 +564,8 @@ __git_ps1 ()
 		b="\${__git_ps1_branch_name}"
 	fi
 
-	local f="$w$i$s$u"
-	local gitstring="$c$b${f:+$z$f}$r$p"
+	local f="$h$w$i$s$u"
+	local gitstring="$c$b${f:+$z$f}${sparse}$r$p"
 
 	if [ $pcmode = yes ]; then
 		if [ "${__git_printf_supports_v-}" != yes ]; then
diff --git a/wt-status.c b/wt-status.c
index 98dfa6f..c560cbe 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -1484,6 +1484,18 @@ static void show_bisect_in_progress(struct wt_status *s,
 	wt_longstatus_print_trailer(s);
 }
 
+static void show_sparse_checkout_in_use(struct wt_status *s,
+					const char *color)
+{
+	if (s->state.sparse_checkout_percentage == SPARSE_CHECKOUT_DISABLED)
+		return;
+
+	status_printf_ln(s, color,
+			 _("You are in a sparse checkout with %d%% of tracked files present."),
+			 s->state.sparse_checkout_percentage);
+	wt_longstatus_print_trailer(s);
+}
+
 /*
  * Extract branch information from rebase/bisect
  */
@@ -1623,6 +1635,31 @@ int wt_status_check_bisect(const struct worktree *wt,
 	return 0;
 }
 
+static void wt_status_check_sparse_checkout(struct repository *r,
+					    struct wt_status_state *state)
+{
+	int skip_worktree = 0;
+	int i;
+
+	if (!core_apply_sparse_checkout || r->index->cache_nr == 0) {
+		/*
+		 * Don't compute percentage of checked out files if we
+		 * aren't in a sparse checkout or would get division by 0.
+		 */
+		state->sparse_checkout_percentage = SPARSE_CHECKOUT_DISABLED;
+		return;
+	}
+
+	for (i = 0; i < r->index->cache_nr; i++) {
+		struct cache_entry *ce = r->index->cache[i];
+		if (ce_skip_worktree(ce))
+			skip_worktree++;
+	}
+
+	state->sparse_checkout_percentage =
+		100 - (100 * skip_worktree)/r->index->cache_nr;
+}
+
 void wt_status_get_state(struct repository *r,
 			 struct wt_status_state *state,
 			 int get_detached_from)
@@ -1658,6 +1695,7 @@ void wt_status_get_state(struct repository *r,
 	}
 	if (get_detached_from)
 		wt_status_get_detached_from(r, state);
+	wt_status_check_sparse_checkout(r, state);
 }
 
 static void wt_longstatus_print_state(struct wt_status *s)
@@ -1681,6 +1719,9 @@ static void wt_longstatus_print_state(struct wt_status *s)
 		show_revert_in_progress(s, state_color);
 	if (state->bisect_in_progress)
 		show_bisect_in_progress(s, state_color);
+
+	if (state->sparse_checkout_percentage != SPARSE_CHECKOUT_DISABLED)
+		show_sparse_checkout_in_use(s, state_color);
 }
 
 static void wt_longstatus_print(struct wt_status *s)
diff --git a/wt-status.h b/wt-status.h
index 73ab5d4..f1fa0ec 100644
--- a/wt-status.h
+++ b/wt-status.h
@@ -79,6 +79,7 @@ enum wt_status_format {
 
 #define HEAD_DETACHED_AT _("HEAD detached at ")
 #define HEAD_DETACHED_FROM _("HEAD detached from ")
+#define SPARSE_CHECKOUT_DISABLED -1
 
 struct wt_status_state {
 	int merge_in_progress;
@@ -90,6 +91,7 @@ struct wt_status_state {
 	int bisect_in_progress;
 	int revert_in_progress;
 	int detached_at;
+	int sparse_checkout_percentage; /* SPARSE_CHECKOUT_DISABLED if not sparse */
 	char *branch;
 	char *onto;
 	char *detached_from;