Merge branch 'ab/read-tree'

Code simplification by removing support for a caller that is long gone.

* ab/read-tree:
  tree.h API: simplify read_tree_recursive() signature
  tree.h API: expose read_tree_1() as read_tree_at()
  archive: stop passing "stage" through read_tree_recursive()
  ls-files: refactor away read_tree()
  ls-files: don't needlessly pass around stage variable
  tree.c API: move read_tree() into builtin/ls-files.c
  ls-files tests: add meaningful --with-tree tests
  show tests: add test for "git show <tree>"

11 files changed, 205 insertions, 147 deletions

diff --git a/archive.c b/archive.c
index 2dd2236ae0..295615580d 100644
--- a/archive.c
+++ b/archive.c
@@ -104,7 +104,6 @@ struct directory {
 	struct object_id oid;
 	int baselen, len;
 	unsigned mode;
-	int stage;
 	char path[FLEX_ARRAY];
 };
 
@@ -135,7 +134,7 @@ static int check_attr_export_subst(const struct attr_check *check)
 }
 
 static int write_archive_entry(const struct object_id *oid, const char *base,
-		int baselen, const char *filename, unsigned mode, int stage,
+		int baselen, const char *filename, unsigned mode,
 		void *context)
 {
 	static struct strbuf path = STRBUF_INIT;
@@ -194,7 +193,7 @@ static int write_archive_entry(const struct object_id *oid, const char *base,
 
 static void queue_directory(const unsigned char *sha1,
 		struct strbuf *base, const char *filename,
-		unsigned mode, int stage, struct archiver_context *c)
+		unsigned mode, struct archiver_context *c)
 {
 	struct directory *d;
 	size_t len = st_add4(base->len, 1, strlen(filename), 1);
@@ -202,7 +201,6 @@ static void queue_directory(const unsigned char *sha1,
 	d->up	   = c->bottom;
 	d->baselen = base->len;
 	d->mode	   = mode;
-	d->stage   = stage;
 	c->bottom  = d;
 	d->len = xsnprintf(d->path, len, "%.*s%s/", (int)base->len, base->buf, filename);
 	hashcpy(d->oid.hash, sha1);
@@ -221,14 +219,14 @@ static int write_directory(struct archiver_context *c)
 		write_directory(c) ||
 		write_archive_entry(&d->oid, d->path, d->baselen,
 				    d->path + d->baselen, d->mode,
-				    d->stage, c) != READ_TREE_RECURSIVE;
+				    c) != READ_TREE_RECURSIVE;
 	free(d);
 	return ret ? -1 : 0;
 }
 
 static int queue_or_write_archive_entry(const struct object_id *oid,
 		struct strbuf *base, const char *filename,
-		unsigned mode, int stage, void *context)
+		unsigned mode, void *context)
 {
 	struct archiver_context *c = context;
 
@@ -253,14 +251,14 @@ static int queue_or_write_archive_entry(const struct object_id *oid,
 		if (check_attr_export_ignore(check))
 			return 0;
 		queue_directory(oid->hash, base, filename,
-				mode, stage, c);
+				mode, c);
 		return READ_TREE_RECURSIVE;
 	}
 
 	if (write_directory(c))
 		return -1;
 	return write_archive_entry(oid, base->buf, base->len, filename, mode,
-				   stage, context);
+				   context);
 }
 
 struct extra_file_info {
@@ -313,10 +311,10 @@ int write_archive_entries(struct archiver_args *args,
 		git_attr_set_direction(GIT_ATTR_INDEX);
 	}
 
-	err = read_tree_recursive(args->repo, args->tree, "",
-				  0, 0, &args->pathspec,
-				  queue_or_write_archive_entry,
-				  &context);
+	err = read_tree(args->repo, args->tree,
+			&args->pathspec,
+			queue_or_write_archive_entry,
+			&context);
 	if (err == READ_TREE_RECURSIVE)
 		err = 0;
 	while (context.bottom) {
@@ -375,7 +373,7 @@ struct path_exists_context {
 
 static int reject_entry(const struct object_id *oid, struct strbuf *base,
 			const char *filename, unsigned mode,
-			int stage, void *context)
+			void *context)
 {
 	int ret = -1;
 	struct path_exists_context *ctx = context;
@@ -402,9 +400,9 @@ static int path_exists(struct archiver_args *args, const char *path)
 	ctx.args = args;
 	parse_pathspec(&ctx.pathspec, 0, 0, "", paths);
 	ctx.pathspec.recursive = 1;
-	ret = read_tree_recursive(args->repo, args->tree, "",
-				  0, 0, &ctx.pathspec,
-				  reject_entry, &ctx);
+	ret = read_tree(args->repo, args->tree,
+			&ctx.pathspec,
+			reject_entry, &ctx);
 	clear_pathspec(&ctx.pathspec);
 	return ret != 0;
 }
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 2d6550bc3c..0e66390520 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -114,7 +114,7 @@ static int post_checkout_hook(struct commit *old_commit, struct commit *new_comm
 }
 
 static int update_some(const struct object_id *oid, struct strbuf *base,
-		const char *pathname, unsigned mode, int stage, void *context)
+		const char *pathname, unsigned mode, void *context)
 {
 	int len;
 	struct cache_entry *ce;
@@ -155,8 +155,8 @@ static int update_some(const struct object_id *oid, struct strbuf *base,
 
 static int read_tree_some(struct tree *tree, const struct pathspec *pathspec)
 {
-	read_tree_recursive(the_repository, tree, "", 0, 0,
-			    pathspec, update_some, NULL);
+	read_tree(the_repository, tree,
+		  pathspec, update_some, NULL);
 
 	/* update the index with the given tree's info
 	 * for all args, expanding wildcards, and exit
@@ -322,7 +322,7 @@ static void mark_ce_for_checkout_overlay(struct cache_entry *ce,
 	 * If it comes from the tree-ish, we already know it
 	 * matches the pathspec and could just stamp
 	 * CE_MATCHED to it from update_some(). But we still
-	 * need ps_matched and read_tree_recursive (and
+	 * need ps_matched and read_tree (and
 	 * eventually tree_entry_interesting) cannot fill
 	 * ps_matched yet. Once it can, we can avoid calling
 	 * match_pathspec() for _all_ entries when
diff --git a/builtin/log.c b/builtin/log.c
index f67b67d80e..980de59063 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -599,7 +599,7 @@ static int show_tag_object(const struct object_id *oid, struct rev_info *rev)
 
 static int show_tree_object(const struct object_id *oid,
 		struct strbuf *base,
-		const char *pathname, unsigned mode, int stage, void *context)
+		const char *pathname, unsigned mode, void *context)
 {
 	FILE *file = context;
 	fprintf(file, "%s%s\n", pathname, S_ISDIR(mode) ? "/" : "");
@@ -681,9 +681,9 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 					diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
 					name,
 					diff_get_color_opt(&rev.diffopt, DIFF_RESET));
-			read_tree_recursive(the_repository, (struct tree *)o, "",
-					    0, 0, &match_all, show_tree_object,
-					    rev.diffopt.file);
+			read_tree(the_repository, (struct tree *)o,
+				  &match_all, show_tree_object,
+				  rev.diffopt.file);
 			rev.shown_one = 1;
 			break;
 		case OBJ_COMMIT:
diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index f6f9e483b2..60a2913a01 100644
--- a/builtin/ls-files.c
+++ b/builtin/ls-files.c
@@ -12,6 +12,7 @@
 #include "dir.h"
 #include "builtin.h"
 #include "tree.h"
+#include "cache-tree.h"
 #include "parse-options.h"
 #include "resolve-undo.h"
 #include "string-list.h"
@@ -420,6 +421,53 @@ static int get_common_prefix_len(const char *common_prefix)
 	return common_prefix_len;
 }
 
+static int read_one_entry_opt(struct index_state *istate,
+			      const struct object_id *oid,
+			      struct strbuf *base,
+			      const char *pathname,
+			      unsigned mode, int opt)
+{
+	int len;
+	struct cache_entry *ce;
+
+	if (S_ISDIR(mode))
+		return READ_TREE_RECURSIVE;
+
+	len = strlen(pathname);
+	ce = make_empty_cache_entry(istate, base->len + len);
+
+	ce->ce_mode = create_ce_mode(mode);
+	ce->ce_flags = create_ce_flags(1);
+	ce->ce_namelen = base->len + len;
+	memcpy(ce->name, base->buf, base->len);
+	memcpy(ce->name + base->len, pathname, len+1);
+	oidcpy(&ce->oid, oid);
+	return add_index_entry(istate, ce, opt);
+}
+
+static int read_one_entry(const struct object_id *oid, struct strbuf *base,
+			  const char *pathname, unsigned mode,
+			  void *context)
+{
+	struct index_state *istate = context;
+	return read_one_entry_opt(istate, oid, base, pathname,
+				  mode,
+				  ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
+}
+
+/*
+ * This is used when the caller knows there is no existing entries at
+ * the stage that will conflict with the entry being added.
+ */
+static int read_one_entry_quick(const struct object_id *oid, struct strbuf *base,
+				const char *pathname, unsigned mode,
+				void *context)
+{
+	struct index_state *istate = context;
+	return read_one_entry_opt(istate, oid, base, pathname,
+				  mode, ADD_CACHE_JUST_APPEND);
+}
+
 /*
  * Read the tree specified with --with-tree option
  * (typically, HEAD) into stage #1 and then
@@ -436,6 +484,8 @@ void overlay_tree_on_index(struct index_state *istate,
 	struct pathspec pathspec;
 	struct cache_entry *last_stage0 = NULL;
 	int i;
+	read_tree_fn_t fn = NULL;
+	int err;
 
 	if (get_oid(tree_name, &oid))
 		die("tree-ish %s not found.", tree_name);
@@ -458,9 +508,32 @@ void overlay_tree_on_index(struct index_state *istate,
 			       PATHSPEC_PREFER_CWD, prefix, matchbuf);
 	} else
 		memset(&pathspec, 0, sizeof(pathspec));
-	if (read_tree(the_repository, tree, 1, &pathspec, istate))
+
+	/*
+	 * See if we have cache entry at the stage.  If so,
+	 * do it the original slow way, otherwise, append and then
+	 * sort at the end.
+	 */
+	for (i = 0; !fn && i < istate->cache_nr; i++) {
+		const struct cache_entry *ce = istate->cache[i];
+		if (ce_stage(ce) == 1)
+			fn = read_one_entry;
+	}
+
+	if (!fn)
+		fn = read_one_entry_quick;
+	err = read_tree(the_repository, tree, &pathspec, fn, istate);
+	if (err)
 		die("unable to read tree entries %s", tree_name);
 
+	/*
+	 * Sort the cache entry -- we need to nuke the cache tree, though.
+	 */
+	if (fn == read_one_entry_quick) {
+		cache_tree_free(&istate->cache_tree);
+		QSORT(istate->cache, istate->cache_nr, cmp_cache_name_compare);
+	}
+
 	for (i = 0; i < istate->cache_nr; i++) {
 		struct cache_entry *ce = istate->cache[i];
 		switch (ce_stage(ce)) {
diff --git a/builtin/ls-tree.c b/builtin/ls-tree.c
index 7cad3f24eb..3a442631c7 100644
--- a/builtin/ls-tree.c
+++ b/builtin/ls-tree.c
@@ -62,7 +62,7 @@ static int show_recursive(const char *base, int baselen, const char *pathname)
 }
 
 static int show_tree(const struct object_id *oid, struct strbuf *base,
-		const char *pathname, unsigned mode, int stage, void *context)
+		const char *pathname, unsigned mode, void *context)
 {
 	int retval = 0;
 	int baselen;
@@ -185,6 +185,6 @@ int cmd_ls_tree(int argc, const char **argv, const char *prefix)
 	tree = parse_tree_indirect(&oid);
 	if (!tree)
 		die("not a tree object");
-	return !!read_tree_recursive(the_repository, tree, "", 0, 0,
-				     &pathspec, show_tree, NULL);
+	return !!read_tree(the_repository, tree,
+			   &pathspec, show_tree, NULL);
 }
diff --git a/cache.h b/cache.h
index 4f0b29bfe4..57f2285bba 100644
--- a/cache.h
+++ b/cache.h
@@ -803,7 +803,7 @@ static inline int index_pos_to_insert_pos(uintmax_t pos)
 #define ADD_CACHE_OK_TO_ADD 1		/* Ok to add */
 #define ADD_CACHE_OK_TO_REPLACE 2	/* Ok to replace file/directory */
 #define ADD_CACHE_SKIP_DFCHECK 4	/* Ok to skip DF conflict checks */
-#define ADD_CACHE_JUST_APPEND 8		/* Append only; tree.c::read_tree() */
+#define ADD_CACHE_JUST_APPEND 8		/* Append only */
 #define ADD_CACHE_NEW_ONLY 16		/* Do not replace existing ones */
 #define ADD_CACHE_KEEP_CACHE_TREE 32	/* Do not invalidate cache-tree */
 #define ADD_CACHE_RENORMALIZE 64        /* Pass along HASH_RENORMALIZE */
diff --git a/merge-recursive.c b/merge-recursive.c
index b69e694d98..ed31f9496c 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -453,7 +453,7 @@ static void unpack_trees_finish(struct merge_options *opt)
 
 static int save_files_dirs(const struct object_id *oid,
 			   struct strbuf *base, const char *path,
-			   unsigned int mode, int stage, void *context)
+			   unsigned int mode, void *context)
 {
 	struct path_hashmap_entry *entry;
 	int baselen = base->len;
@@ -473,8 +473,8 @@ static void get_files_dirs(struct merge_options *opt, struct tree *tree)
 {
 	struct pathspec match_all;
 	memset(&match_all, 0, sizeof(match_all));
-	read_tree_recursive(opt->repo, tree, "", 0, 0,
-			    &match_all, save_files_dirs, opt);
+	read_tree(opt->repo, tree,
+		  &match_all, save_files_dirs, opt);
 }
 
 static int get_tree_entry_if_blob(struct repository *r,
diff --git a/t/t3060-ls-files-with-tree.sh b/t/t3060-ls-files-with-tree.sh
index 52ed665fcd..b257c792a4 100755
--- a/t/t3060-ls-files-with-tree.sh
+++ b/t/t3060-ls-files-with-tree.sh
@@ -47,6 +47,12 @@ test_expect_success setup '
 	git add .
 '
 
+test_expect_success 'usage' '
+	test_expect_code 128 git ls-files --with-tree=HEAD -u &&
+	test_expect_code 128 git ls-files --with-tree=HEAD -s &&
+	test_expect_code 128 git ls-files --recurse-submodules --with-tree=HEAD
+'
+
 test_expect_success 'git ls-files --with-tree should succeed from subdir' '
 	# We have to run from a sub-directory to trigger prune_path
 	# Then we finally get to run our --with-tree test
@@ -60,4 +66,39 @@ test_expect_success \
     'git ls-files --with-tree should add entries from named tree.' \
     'test_cmp expected output'
 
+test_expect_success 'no duplicates in --with-tree output' '
+	git ls-files --with-tree=HEAD >actual &&
+	sort -u actual >expected &&
+	test_cmp expected actual
+'
+
+test_expect_success 'setup: output in a conflict' '
+	test_create_repo conflict &&
+	test_commit -C conflict BASE file &&
+	test_commit -C conflict A file foo &&
+	git -C conflict reset --hard BASE &&
+	test_commit -C conflict B file bar
+'
+
+test_expect_success 'output in a conflict' '
+	test_must_fail git -C conflict merge A B &&
+	cat >expected <<-\EOF &&
+	file
+	file
+	file
+	file
+	EOF
+	git -C conflict ls-files --with-tree=HEAD >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'output with removed .git/index' '
+	cat >expected <<-\EOF &&
+	file
+	EOF
+	rm conflict/.git/index &&
+	git -C conflict ls-files --with-tree=HEAD >actual &&
+	test_cmp expected actual
+'
+
 test_done
diff --git a/t/t7007-show.sh b/t/t7007-show.sh
index 42d3db6246..d6cc69e0f2 100755
--- a/t/t7007-show.sh
+++ b/t/t7007-show.sh
@@ -38,6 +38,45 @@ test_expect_success 'showing two commits' '
 	test_cmp expect actual.filtered
 '
 
+test_expect_success 'showing a tree' '
+	cat >expected <<-EOF &&
+	tree main1:
+
+	main1.t
+	EOF
+	git show main1: >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'showing two trees' '
+	cat >expected <<-EOF &&
+	tree main1^{tree}
+
+	main1.t
+
+	tree main2^{tree}
+
+	main1.t
+	main2.t
+	EOF
+	git show main1^{tree} main2^{tree} >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'showing a trees is not recursive' '
+	git worktree add not-recursive main1 &&
+	mkdir not-recursive/a &&
+	test_commit -C not-recursive a/file &&
+	cat >expected <<-EOF &&
+	tree HEAD^{tree}
+
+	a/
+	main1.t
+	EOF
+	git -C not-recursive show HEAD^{tree} >actual &&
+	test_cmp expected actual
+'
+
 test_expect_success 'showing a range walks (linear)' '
 	cat >expect <<-EOF &&
 	commit $(git rev-parse main3)
diff --git a/tree.c b/tree.c
index a52479812c..410e3b477e 100644
--- a/tree.c
+++ b/tree.c
@@ -11,58 +11,10 @@
 
 const char *tree_type = "tree";
 
-static int read_one_entry_opt(struct index_state *istate,
-			      const struct object_id *oid,
-			      const char *base, int baselen,
-			      const char *pathname,
-			      unsigned mode, int stage, int opt)
-{
-	int len;
-	struct cache_entry *ce;
-
-	if (S_ISDIR(mode))
-		return READ_TREE_RECURSIVE;
-
-	len = strlen(pathname);
-	ce = make_empty_cache_entry(istate, baselen + len);
-
-	ce->ce_mode = create_ce_mode(mode);
-	ce->ce_flags = create_ce_flags(stage);
-	ce->ce_namelen = baselen + len;
-	memcpy(ce->name, base, baselen);
-	memcpy(ce->name + baselen, pathname, len+1);
-	oidcpy(&ce->oid, oid);
-	return add_index_entry(istate, ce, opt);
-}
-
-static int read_one_entry(const struct object_id *oid, struct strbuf *base,
-			  const char *pathname, unsigned mode, int stage,
-			  void *context)
-{
-	struct index_state *istate = context;
-	return read_one_entry_opt(istate, oid, base->buf, base->len, pathname,
-				  mode, stage,
-				  ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
-}
-
-/*
- * This is used when the caller knows there is no existing entries at
- * the stage that will conflict with the entry being added.
- */
-static int read_one_entry_quick(const struct object_id *oid, struct strbuf *base,
-				const char *pathname, unsigned mode, int stage,
-				void *context)
-{
-	struct index_state *istate = context;
-	return read_one_entry_opt(istate, oid, base->buf, base->len, pathname,
-				  mode, stage,
-				  ADD_CACHE_JUST_APPEND);
-}
-
-static int read_tree_1(struct repository *r,
-		       struct tree *tree, struct strbuf *base,
-		       int stage, const struct pathspec *pathspec,
-		       read_tree_fn_t fn, void *context)
+int read_tree_at(struct repository *r,
+		 struct tree *tree, struct strbuf *base,
+		 const struct pathspec *pathspec,
+		 read_tree_fn_t fn, void *context)
 {
 	struct tree_desc desc;
 	struct name_entry entry;
@@ -86,7 +38,7 @@ static int read_tree_1(struct repository *r,
 		}
 
 		switch (fn(&entry.oid, base,
-			   entry.path, entry.mode, stage, context)) {
+			   entry.path, entry.mode, context)) {
 		case 0:
 			continue;
 		case READ_TREE_RECURSIVE:
@@ -119,9 +71,9 @@ static int read_tree_1(struct repository *r,
 		len = tree_entry_len(&entry);
 		strbuf_add(base, entry.path, len);
 		strbuf_addch(base, '/');
-		retval = read_tree_1(r, lookup_tree(r, &oid),
-				     base, stage, pathspec,
-				     fn, context);
+		retval = read_tree_at(r, lookup_tree(r, &oid),
+				      base, pathspec,
+				      fn, context);
 		strbuf_setlen(base, oldlen);
 		if (retval)
 			return -1;
@@ -129,17 +81,13 @@ static int read_tree_1(struct repository *r,
 	return 0;
 }
 
-int read_tree_recursive(struct repository *r,
-			struct tree *tree,
-			const char *base, int baselen,
-			int stage, const struct pathspec *pathspec,
-			read_tree_fn_t fn, void *context)
+int read_tree(struct repository *r,
+	      struct tree *tree,
+	      const struct pathspec *pathspec,
+	      read_tree_fn_t fn, void *context)
 {
 	struct strbuf sb = STRBUF_INIT;
-	int ret;
-
-	strbuf_add(&sb, base, baselen);
-	ret = read_tree_1(r, tree, &sb, stage, pathspec, fn, context);
+	int ret = read_tree_at(r, tree, &sb, pathspec, fn, context);
 	strbuf_release(&sb);
 	return ret;
 }
@@ -154,47 +102,6 @@ int cmp_cache_name_compare(const void *a_, const void *b_)
 				  ce2->name, ce2->ce_namelen, ce_stage(ce2));
 }
 
-int read_tree(struct repository *r, struct tree *tree, int stage,
-	      struct pathspec *match, struct index_state *istate)
-{
-	read_tree_fn_t fn = NULL;
-	int i, err;
-
-	/*
-	 * Currently the only existing callers of this function all
-	 * call it with stage=1 and after making sure there is nothing
-	 * at that stage; we could always use read_one_entry_quick().
-	 *
-	 * But when we decide to straighten out git-read-tree not to
-	 * use unpack_trees() in some cases, this will probably start
-	 * to matter.
-	 */
-
-	/*
-	 * See if we have cache entry at the stage.  If so,
-	 * do it the original slow way, otherwise, append and then
-	 * sort at the end.
-	 */
-	for (i = 0; !fn && i < istate->cache_nr; i++) {
-		const struct cache_entry *ce = istate->cache[i];
-		if (ce_stage(ce) == stage)
-			fn = read_one_entry;
-	}
-
-	if (!fn)
-		fn = read_one_entry_quick;
-	err = read_tree_recursive(r, tree, "", 0, stage, match, fn, istate);
-	if (fn == read_one_entry || err)
-		return err;
-
-	/*
-	 * Sort the cache entry -- we need to nuke the cache tree, though.
-	 */
-	cache_tree_free(&istate->cache_tree);
-	QSORT(istate->cache, istate->cache_nr, cmp_cache_name_compare);
-	return 0;
-}
-
 struct tree *lookup_tree(struct repository *r, const struct object_id *oid)
 {
 	struct object *obj = lookup_object(r, oid);
diff --git a/tree.h b/tree.h
index 3eb0484cbf..6efff003e2 100644
--- a/tree.h
+++ b/tree.h
@@ -31,16 +31,16 @@ struct tree *parse_tree_indirect(const struct object_id *oid);
 int cmp_cache_name_compare(const void *a_, const void *b_);
 
 #define READ_TREE_RECURSIVE 1
-typedef int (*read_tree_fn_t)(const struct object_id *, struct strbuf *, const char *, unsigned int, int, void *);
+typedef int (*read_tree_fn_t)(const struct object_id *, struct strbuf *, const char *, unsigned int, void *);
 
-int read_tree_recursive(struct repository *r,
-			struct tree *tree,
-			const char *base, int baselen,
-			int stage, const struct pathspec *pathspec,
-			read_tree_fn_t fn, void *context);
+int read_tree_at(struct repository *r,
+		 struct tree *tree, struct strbuf *base,
+		 const struct pathspec *pathspec,
+		 read_tree_fn_t fn, void *context);
 
-int read_tree(struct repository *r, struct tree *tree,
-	      int stage, struct pathspec *pathspec,
-	      struct index_state *istate);
+int read_tree(struct repository *r,
+	      struct tree *tree,
+	      const struct pathspec *pathspec,
+	      read_tree_fn_t fn, void *context);
 
 #endif /* TREE_H */