1 files changed, 187 insertions, 76 deletions

diff --git a/unpack-trees.c b/unpack-trees.c
index 01c9149121..4be5fc3075 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -24,7 +24,7 @@
  * situation better.  See how "git checkout" and "git merge" replaces
  * them using setup_unpack_trees_porcelain(), for example.
  */
-static const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
+static const char *unpack_plumbing_errors[NB_UNPACK_TREES_WARNING_TYPES] = {
 	/* ERROR_WOULD_OVERWRITE */
 	"Entry '%s' would be overwritten by merge. Cannot merge.",
 
@@ -43,17 +43,20 @@ static const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
 	/* ERROR_BIND_OVERLAP */
 	"Entry '%s' overlaps with '%s'.  Cannot bind.",
 
-	/* ERROR_SPARSE_NOT_UPTODATE_FILE */
-	"Entry '%s' not uptodate. Cannot update sparse checkout.",
+	/* ERROR_WOULD_LOSE_SUBMODULE */
+	"Submodule '%s' cannot checkout new HEAD.",
 
-	/* ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN */
-	"Working tree file '%s' would be overwritten by sparse checkout update.",
+	/* NB_UNPACK_TREES_ERROR_TYPES; just a meta value */
+	"",
 
-	/* ERROR_WOULD_LOSE_ORPHANED_REMOVED */
-	"Working tree file '%s' would be removed by sparse checkout update.",
+	/* WARNING_SPARSE_NOT_UPTODATE_FILE */
+	"Path '%s' not uptodate; will not remove from working tree.",
 
-	/* ERROR_WOULD_LOSE_SUBMODULE */
-	"Submodule '%s' cannot checkout new HEAD.",
+	/* WARNING_SPARSE_UNMERGED_FILE */
+	"Path '%s' unmerged; will not remove from working tree.",
+
+	/* WARNING_SPARSE_ORPHANED_NOT_OVERWRITTEN */
+	"Path '%s' already present; will not overwrite with sparse update.",
 };
 
 #define ERRORMSG(o,type) \
@@ -168,15 +171,16 @@ void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
 	 */
 	msgs[ERROR_BIND_OVERLAP] = _("Entry '%s' overlaps with '%s'.  Cannot bind.");
 
-	msgs[ERROR_SPARSE_NOT_UPTODATE_FILE] =
-		_("Cannot update sparse checkout: the following entries are not up to date:\n%s");
-	msgs[ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN] =
-		_("The following working tree files would be overwritten by sparse checkout update:\n%s");
-	msgs[ERROR_WOULD_LOSE_ORPHANED_REMOVED] =
-		_("The following working tree files would be removed by sparse checkout update:\n%s");
 	msgs[ERROR_WOULD_LOSE_SUBMODULE] =
 		_("Cannot update submodule:\n%s");
 
+	msgs[WARNING_SPARSE_NOT_UPTODATE_FILE] =
+		_("The following paths are not up to date and were left despite sparse patterns:\n%s");
+	msgs[WARNING_SPARSE_UNMERGED_FILE] =
+		_("The following paths are unmerged and were left despite sparse patterns:\n%s");
+	msgs[WARNING_SPARSE_ORPHANED_NOT_OVERWRITTEN] =
+		_("The following paths were already present and thus not updated despite sparse patterns:\n%s");
+
 	opts->show_all_errors = 1;
 	/* rejected paths may not have a static buffer */
 	for (i = 0; i < ARRAY_SIZE(opts->unpack_rejects); i++)
@@ -226,7 +230,7 @@ static int add_rejected_path(struct unpack_trees_options *o,
 
 	/*
 	 * Otherwise, insert in a list for future display by
-	 * display_error_msgs()
+	 * display_(error|warning)_msgs()
 	 */
 	string_list_append(&o->unpack_rejects[e], path);
 	return -1;
@@ -237,13 +241,16 @@ static int add_rejected_path(struct unpack_trees_options *o,
  */
 static void display_error_msgs(struct unpack_trees_options *o)
 {
-	int e, i;
-	int something_displayed = 0;
+	int e;
+	unsigned error_displayed = 0;
 	for (e = 0; e < NB_UNPACK_TREES_ERROR_TYPES; e++) {
 		struct string_list *rejects = &o->unpack_rejects[e];
+
 		if (rejects->nr > 0) {
+			int i;
 			struct strbuf path = STRBUF_INIT;
-			something_displayed = 1;
+
+			error_displayed = 1;
 			for (i = 0; i < rejects->nr; i++)
 				strbuf_addf(&path, "\t%s\n", rejects->items[i].string);
 			error(ERRORMSG(o, e), super_prefixed(path.buf));
@@ -251,10 +258,36 @@ static void display_error_msgs(struct unpack_trees_options *o)
 		}
 		string_list_clear(rejects, 0);
 	}
-	if (something_displayed)
+	if (error_displayed)
 		fprintf(stderr, _("Aborting\n"));
 }
 
+/*
+ * display all the warning messages stored in a nice way
+ */
+static void display_warning_msgs(struct unpack_trees_options *o)
+{
+	int e;
+	unsigned warning_displayed = 0;
+	for (e = NB_UNPACK_TREES_ERROR_TYPES + 1;
+	     e < NB_UNPACK_TREES_WARNING_TYPES; e++) {
+		struct string_list *rejects = &o->unpack_rejects[e];
+
+		if (rejects->nr > 0) {
+			int i;
+			struct strbuf path = STRBUF_INIT;
+
+			warning_displayed = 1;
+			for (i = 0; i < rejects->nr; i++)
+				strbuf_addf(&path, "\t%s\n", rejects->items[i].string);
+			warning(ERRORMSG(o, e), super_prefixed(path.buf));
+			strbuf_release(&path);
+		}
+		string_list_clear(rejects, 0);
+	}
+	if (warning_displayed)
+		fprintf(stderr, _("After fixing the above paths, you may want to run `git sparse-checkout reapply`.\n"));
+}
 static int check_submodule_move_head(const struct cache_entry *ce,
 				     const char *old_id,
 				     const char *new_id,
@@ -300,10 +333,10 @@ static void load_gitmodules_file(struct index_state *index,
 	}
 }
 
-static struct progress *get_progress(struct unpack_trees_options *o)
+static struct progress *get_progress(struct unpack_trees_options *o,
+				     struct index_state *index)
 {
 	unsigned cnt = 0, total = 0;
-	struct index_state *index = &o->result;
 
 	if (!o->update || !o->verbose_update)
 		return NULL;
@@ -357,12 +390,12 @@ static void report_collided_checkout(struct index_state *index)
 	string_list_clear(&list, 0);
 }
 
-static int check_updates(struct unpack_trees_options *o)
+static int check_updates(struct unpack_trees_options *o,
+			 struct index_state *index)
 {
 	unsigned cnt = 0;
 	int errs = 0;
 	struct progress *progress;
-	struct index_state *index = &o->result;
 	struct checkout state = CHECKOUT_INIT;
 	int i;
 
@@ -371,6 +404,7 @@ static int check_updates(struct unpack_trees_options *o)
 	state.quiet = 1;
 	state.refresh_cache = 1;
 	state.istate = index;
+	clone_checkout_metadata(&state.meta, &o->meta, NULL);
 
 	if (!o->update || o->dry_run) {
 		remove_marked_cache_entries(index, 0);
@@ -381,7 +415,7 @@ static int check_updates(struct unpack_trees_options *o)
 	if (o->clone)
 		setup_collided_checkout_detection(&state, index);
 
-	progress = get_progress(o);
+	progress = get_progress(o, index);
 
 	git_attr_set_direction(GIT_ATTR_CHECKOUT);
 
@@ -503,19 +537,39 @@ static int apply_sparse_checkout(struct index_state *istate,
 		 * also stat info may have lost after merged_entry() so calling
 		 * verify_uptodate() again may fail
 		 */
-		if (!(ce->ce_flags & CE_UPDATE) && verify_uptodate_sparse(ce, o))
+		if (!(ce->ce_flags & CE_UPDATE) &&
+		    verify_uptodate_sparse(ce, o)) {
+			ce->ce_flags &= ~CE_SKIP_WORKTREE;
 			return -1;
+		}
 		ce->ce_flags |= CE_WT_REMOVE;
 		ce->ce_flags &= ~CE_UPDATE;
 	}
 	if (was_skip_worktree && !ce_skip_worktree(ce)) {
-		if (verify_absent_sparse(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
+		if (verify_absent_sparse(ce, WARNING_SPARSE_ORPHANED_NOT_OVERWRITTEN, o))
 			return -1;
 		ce->ce_flags |= CE_UPDATE;
 	}
 	return 0;
 }
 
+static int warn_conflicted_path(struct index_state *istate,
+				int i,
+				struct unpack_trees_options *o)
+{
+	char *conflicting_path = istate->cache[i]->name;
+	int count = 0;
+
+	add_rejected_path(o, WARNING_SPARSE_UNMERGED_FILE, conflicting_path);
+
+	/* Find out how many higher stage entries are at same path */
+	while ((++count) + i < istate->cache_nr &&
+	       !strcmp(conflicting_path, istate->cache[count + i]->name))
+		; /* do nothing */
+
+	return count;
+}
+
 static inline int call_unpack_fn(const struct cache_entry * const *src,
 				 struct unpack_trees_options *o)
 {
@@ -1492,6 +1546,20 @@ static void mark_new_skip_worktree(struct pattern_list *pl,
 	clear_ce_flags(istate, select_flag, skip_wt_flag, pl, show_progress);
 }
 
+static void populate_from_existing_patterns(struct unpack_trees_options *o,
+					    struct pattern_list *pl)
+{
+	char *sparse = git_pathdup("info/sparse-checkout");
+
+	pl->use_cone_patterns = core_sparse_checkout_cone;
+	if (add_patterns_from_file_to_list(sparse, "", 0, pl, NULL) < 0)
+		o->skip_sparse_checkout = 1;
+	else
+		o->pl = pl;
+	free(sparse);
+}
+
+
 static int verify_absent(const struct cache_entry *,
 			 enum unpack_trees_error_types,
 			 struct unpack_trees_options *);
@@ -1506,22 +1574,18 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 	int i, ret;
 	static struct cache_entry *dfc;
 	struct pattern_list pl;
+	int free_pattern_list = 0;
 
 	if (len > MAX_UNPACK_TREES)
 		die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
 
 	trace_performance_enter();
-	memset(&pl, 0, sizeof(pl));
 	if (!core_apply_sparse_checkout || !o->update)
 		o->skip_sparse_checkout = 1;
 	if (!o->skip_sparse_checkout && !o->pl) {
-		char *sparse = git_pathdup("info/sparse-checkout");
-		pl.use_cone_patterns = core_sparse_checkout_cone;
-		if (add_patterns_from_file_to_list(sparse, "", 0, &pl, NULL) < 0)
-			o->skip_sparse_checkout = 1;
-		else
-			o->pl = &pl;
-		free(sparse);
+		memset(&pl, 0, sizeof(pl));
+		free_pattern_list = 1;
+		populate_from_existing_patterns(o, &pl);
 	}
 
 	memset(&o->result, 0, sizeof(o->result));
@@ -1613,11 +1677,9 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 	}
 
 	if (!o->skip_sparse_checkout) {
-		int empty_worktree = 1;
-
 		/*
 		 * Sparse checkout loop #2: set NEW_SKIP_WORKTREE on entries not in loop #1
-		 * If the will have NEW_SKIP_WORKTREE, also set CE_SKIP_WORKTREE
+		 * If they will have NEW_SKIP_WORKTREE, also set CE_SKIP_WORKTREE
 		 * so apply_sparse_checkout() won't attempt to remove it from worktree
 		 */
 		mark_new_skip_worktree(o->pl, &o->result,
@@ -1637,36 +1699,24 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 			 * correct CE_NEW_SKIP_WORKTREE
 			 */
 			if (ce->ce_flags & CE_ADDED &&
-			    verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o)) {
-				if (!o->show_all_errors)
-					goto return_failed;
-				ret = -1;
-			}
-
-			if (apply_sparse_checkout(&o->result, ce, o)) {
-				if (!o->show_all_errors)
-					goto return_failed;
-				ret = -1;
-			}
-			if (!ce_skip_worktree(ce))
-				empty_worktree = 0;
+			    verify_absent(ce, WARNING_SPARSE_ORPHANED_NOT_OVERWRITTEN, o))
+				ret = 1;
 
+			if (apply_sparse_checkout(&o->result, ce, o))
+				ret = 1;
 		}
-		if (ret < 0)
-			goto return_failed;
-		/*
-		 * Sparse checkout is meant to narrow down checkout area
-		 * but it does not make sense to narrow down to empty working
-		 * tree. This is usually a mistake in sparse checkout rules.
-		 * Do not allow users to do that.
-		 */
-		if (o->result.cache_nr && empty_worktree) {
-			ret = unpack_failed(o, "Sparse checkout leaves no entry on working directory");
-			goto done;
+		if (ret == 1) {
+			/*
+			 * Inability to sparsify or de-sparsify individual
+			 * paths is not an error, but just a warning.
+			 */
+			if (o->show_all_errors)
+				display_warning_msgs(o);
+			ret = 0;
 		}
 	}
 
-	ret = check_updates(o) ? (-2) : 0;
+	ret = check_updates(o, &o->result) ? (-2) : 0;
 	if (o->dst_index) {
 		move_index_extensions(&o->result, o->src_index);
 		if (!ret) {
@@ -1689,9 +1739,9 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 	o->src_index = NULL;
 
 done:
-	trace_performance_leave("unpack_trees");
-	if (!o->keep_pattern_list)
+	if (free_pattern_list)
 		clear_pattern_list(&pl);
+	trace_performance_leave("unpack_trees");
 	return ret;
 
 return_failed:
@@ -1704,6 +1754,74 @@ return_failed:
 	goto done;
 }
 
+/*
+ * Update SKIP_WORKTREE bits according to sparsity patterns, and update
+ * working directory to match.
+ *
+ * CE_NEW_SKIP_WORKTREE is used internally.
+ */
+enum update_sparsity_result update_sparsity(struct unpack_trees_options *o)
+{
+	enum update_sparsity_result ret = UPDATE_SPARSITY_SUCCESS;
+	struct pattern_list pl;
+	int i;
+	unsigned old_show_all_errors;
+	int free_pattern_list = 0;
+
+	old_show_all_errors = o->show_all_errors;
+	o->show_all_errors = 1;
+
+	/* Sanity checks */
+	if (!o->update || o->index_only || o->skip_sparse_checkout)
+		BUG("update_sparsity() is for reflecting sparsity patterns in working directory");
+	if (o->src_index != o->dst_index || o->fn)
+		BUG("update_sparsity() called wrong");
+
+	trace_performance_enter();
+
+	/* If we weren't given patterns, use the recorded ones */
+	if (!o->pl) {
+		memset(&pl, 0, sizeof(pl));
+		free_pattern_list = 1;
+		populate_from_existing_patterns(o, &pl);
+		if (o->skip_sparse_checkout)
+			goto skip_sparse_checkout;
+	}
+
+	/* Set NEW_SKIP_WORKTREE on existing entries. */
+	mark_all_ce_unused(o->src_index);
+	mark_new_skip_worktree(o->pl, o->src_index, 0,
+			       CE_NEW_SKIP_WORKTREE, o->verbose_update);
+
+	/* Then loop over entries and update/remove as needed */
+	ret = UPDATE_SPARSITY_SUCCESS;
+	for (i = 0; i < o->src_index->cache_nr; i++) {
+		struct cache_entry *ce = o->src_index->cache[i];
+
+
+		if (ce_stage(ce)) {
+			/* -1 because for loop will increment by 1 */
+			i += warn_conflicted_path(o->src_index, i, o) - 1;
+			ret = UPDATE_SPARSITY_WARNINGS;
+			continue;
+		}
+
+		if (apply_sparse_checkout(o->src_index, ce, o))
+			ret = UPDATE_SPARSITY_WARNINGS;
+	}
+
+skip_sparse_checkout:
+	if (check_updates(o, o->src_index))
+		ret = UPDATE_SPARSITY_WORKTREE_UPDATE_FAILURES;
+
+	display_warning_msgs(o);
+	o->show_all_errors = old_show_all_errors;
+	if (free_pattern_list)
+		clear_pattern_list(&pl);
+	trace_performance_leave("update_sparsity");
+	return ret;
+}
+
 /* Here come the merge functions */
 
 static int reject_merge(const struct cache_entry *ce,
@@ -1788,7 +1906,7 @@ int verify_uptodate(const struct cache_entry *ce,
 static int verify_uptodate_sparse(const struct cache_entry *ce,
 				  struct unpack_trees_options *o)
 {
-	return verify_uptodate_1(ce, o, ERROR_SPARSE_NOT_UPTODATE_FILE);
+	return verify_uptodate_1(ce, o, WARNING_SPARSE_NOT_UPTODATE_FILE);
 }
 
 /*
@@ -1814,9 +1932,6 @@ static void invalidate_ce_path(const struct cache_entry *ce,
 /*
  * Check that checking out ce->sha1 in subdir ce->name is not
  * going to overwrite any working files.
- *
- * Currently, git does not checkout subprojects during a superproject
- * checkout, so it is not going to overwrite anything.
  */
 static int verify_clean_submodule(const char *old_sha1,
 				  const struct cache_entry *ce,
@@ -2029,11 +2144,7 @@ static int verify_absent_sparse(const struct cache_entry *ce,
 				enum unpack_trees_error_types error_type,
 				struct unpack_trees_options *o)
 {
-	enum unpack_trees_error_types orphaned_error = error_type;
-	if (orphaned_error == ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN)
-		orphaned_error = ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN;
-
-	return verify_absent_1(ce, orphaned_error, o);
+	return verify_absent_1(ce, error_type, o);
 }
 
 static int merged_entry(const struct cache_entry *ce,
@@ -2066,7 +2177,7 @@ static int merged_entry(const struct cache_entry *ce,
 		}
 		invalidate_ce_path(merge, o);
 
-		if (submodule_from_ce(ce)) {
+		if (submodule_from_ce(ce) && file_exists(ce->name)) {
 			int ret = check_submodule_move_head(ce, NULL,
 							    oid_to_hex(&ce->oid),
 							    o);
@@ -2095,7 +2206,7 @@ static int merged_entry(const struct cache_entry *ce,
 			invalidate_ce_path(old, o);
 		}
 
-		if (submodule_from_ce(ce)) {
+		if (submodule_from_ce(ce) && file_exists(ce->name)) {
 			int ret = check_submodule_move_head(ce, oid_to_hex(&old->oid),
 							    oid_to_hex(&ce->oid),
 							    o);