[PATCH v3] untracked-cache: fix subdirectory handling

@@ -1297,7 +1297,7 @@ static enum exist_status directory_exists_in_index(const char *dirname, int len)
  */
 static enum path_treatment treat_directory(struct dir_struct *dir,
 	struct untracked_cache_dir *untracked,
-	const char *dirname, int len, int exclude,
+	const char *dirname, int len, int baselen, int exclude,
 	const struct path_simplify *simplify)
 {
 	/* The "len-1" is to strip the final '/' */

@@ -1324,7 +1324,8 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
 	if (!(dir->flags & DIR_HIDE_EMPTY_DIRECTORIES))
 		return exclude ? path_excluded : path_untracked;
 
-	untracked = lookup_untracked(dir->untracked, untracked, dirname, len);
+	untracked = lookup_untracked(dir->untracked, untracked,
+				     dirname + baselen, len - baselen);
 	return read_directory_recursive(dir, dirname, len,
 					untracked, 1, simplify);
 }

@@ -1444,6 +1445,7 @@ static int get_dtype(struct dirent *de, const char *path, int len)
 static enum path_treatment treat_one_path(struct dir_struct *dir,
 					  struct untracked_cache_dir *untracked,
 					  struct strbuf *path,
+					  int baselen,
 					  const struct path_simplify *simplify,
 					  int dtype, struct dirent *de)
 {

@@ -1495,8 +1497,8 @@ static enum path_treatment treat_one_path(struct dir_struct *dir,
 		return path_none;
 	case DT_DIR:
 		strbuf_addch(path, '/');
-		return treat_directory(dir, untracked, path->buf, path->len, exclude,
-			simplify);
+		return treat_directory(dir, untracked, path->buf, path->len,
+				       baselen, exclude, simplify);
 	case DT_REG:
 	case DT_LNK:
 		return exclude ? path_excluded : path_untracked;

@@ -1557,7 +1559,7 @@ static enum path_treatment treat_path(struct dir_struct *dir,
 		return path_none;
 
 	dtype = DTYPE(de);
-	return treat_one_path(dir, untracked, path, simplify, dtype, de);
+	return treat_one_path(dir, untracked, path, baselen, simplify, dtype, de);
 }
 
 static void add_untracked(struct untracked_cache_dir *dir, const char *name)

@@ -1827,7 +1829,7 @@ static int treat_leading_path(struct dir_struct *dir,
 			break;
 		if (simplify_away(sb.buf, sb.len, simplify))
 			break;
-		if (treat_one_path(dir, NULL, &sb, simplify,
+		if (treat_one_path(dir, NULL, &sb, baselen, simplify,
 				   DT_DIR, NULL) == path_none)
 			break; /* do not recurse into it */
 		if (len <= baselen) {

@@ -402,13 +402,14 @@ test_expect_success 'set up sparse checkout' '
 	echo "done/[a-z]*" >.git/info/sparse-checkout &&
 	test_config core.sparsecheckout true &&
 	git checkout master &&
-	git update-index --untracked-cache &&
+	git update-index --untracked-cache --force-untracked-cache &&
 	git status --porcelain >/dev/null && # prime the cache
 	test_path_is_missing done/.gitignore &&
 	test_path_is_file done/one
 '
 
-test_expect_success 'create files, some of which are gitignored' '
+test_expect_success 'create/modify files, some of which are gitignored' '
+	echo two bis >done/two &&
 	echo three >done/three && # three is gitignored
 	echo four >done/four && # four is gitignored at a higher level
 	echo five >done/five # five is not gitignored

@@ -420,6 +421,7 @@ test_expect_success 'test sparse status with untracked cache' '
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../status.actual &&
 	cat >../status.expect <<EOF &&
+ M done/two
 ?? .gitignore
 ?? done/five
 ?? dtwo/

@@ -459,6 +461,7 @@ test_expect_success 'test sparse status again with untracked cache' '
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../status.actual &&
 	cat >../status.expect <<EOF &&
+ M done/two
 ?? .gitignore
 ?? done/five
 ?? dtwo/

@@ -473,4 +476,71 @@ EOF
 	test_cmp ../trace.expect ../trace
 '
 
+test_expect_success 'set up for test of subdir and sparse checkouts' '
+	mkdir done/sub &&
+	mkdir done/sub/sub &&
+	echo "sub" > done/sub/sub/file
+'
+
+test_expect_success 'test sparse status with untracked cache and subdir' '
+	avoid_racy &&
+	: >../trace &&
+	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
+	git status --porcelain >../status.actual &&
+	cat >../status.expect <<EOF &&
+ M done/two
+?? .gitignore
+?? done/five
+?? done/sub/
+?? dtwo/
+EOF
+	test_cmp ../status.expect ../status.actual &&
+	cat >../trace.expect <<EOF &&
+node creation: 2
+gitignore invalidation: 0
+directory invalidation: 1
+opendir: 3
+EOF
+	test_cmp ../trace.expect ../trace
+'
+
+test_expect_success 'verify untracked cache dump (sparse/subdirs)' '
+	test-dump-untracked-cache >../actual &&
+	cat >../expect <<EOF &&
+info/exclude 13263c0978fb9fad16b2d580fb800b6d811c3ff0
+core.excludesfile 0000000000000000000000000000000000000000
+exclude_per_dir .gitignore
+flags 00000006
+/ e6fcc8f2ee31bae321d66afd183fcb7237afae6e recurse valid
+.gitignore
+dtwo/
+/done/ 1946f0437f90c5005533cbe1736a6451ca301714 recurse valid
+five
+sub/
+/done/sub/ 0000000000000000000000000000000000000000 recurse check_only valid
+sub/
+/done/sub/sub/ 0000000000000000000000000000000000000000 recurse check_only valid
+file
+/dthree/ 0000000000000000000000000000000000000000 recurse check_only valid
+/dtwo/ 0000000000000000000000000000000000000000 recurse check_only valid
+two
+EOF
+	test_cmp ../expect ../actual
+'
+
+test_expect_success 'test sparse status again with untracked cache and subdir' '
+	avoid_racy &&
+	: >../trace &&
+	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
+	git status --porcelain >../status.actual &&
+	test_cmp ../status.expect ../status.actual &&
+	cat >../trace.expect <<EOF &&
+node creation: 0
+gitignore invalidation: 0
+directory invalidation: 0
+opendir: 0
+EOF
+	test_cmp ../trace.expect ../trace
+'
+
 test_done

@@ -1297,7 +1297,7 @@ static enum exist_status directory_exists_in_index(const char *dirname, int len)
  */
 static enum path_treatment treat_directory(struct dir_struct *dir,
 	struct untracked_cache_dir *untracked,
-	const char *dirname, int len, int exclude,
+	const char *dirname, int len, int baselen, int exclude,
 	const struct path_simplify *simplify)
 {
 	/* The "len-1" is to strip the final '/' */

@@ -1324,7 +1324,8 @@ static enum path_treatment treat_directory(struct dir_struct *dir,
 	if (!(dir->flags & DIR_HIDE_EMPTY_DIRECTORIES))
 		return exclude ? path_excluded : path_untracked;
 
-	untracked = lookup_untracked(dir->untracked, untracked, dirname, len);
+	untracked = lookup_untracked(dir->untracked, untracked,
+				     dirname + baselen, len - baselen);
 	return read_directory_recursive(dir, dirname, len,
 					untracked, 1, simplify);
 }

@@ -1444,6 +1445,7 @@ static int get_dtype(struct dirent *de, const char *path, int len)
 static enum path_treatment treat_one_path(struct dir_struct *dir,
 					  struct untracked_cache_dir *untracked,
 					  struct strbuf *path,
+					  int baselen,
 					  const struct path_simplify *simplify,
 					  int dtype, struct dirent *de)
 {

@@ -1495,8 +1497,8 @@ static enum path_treatment treat_one_path(struct dir_struct *dir,
 		return path_none;
 	case DT_DIR:
 		strbuf_addch(path, '/');
-		return treat_directory(dir, untracked, path->buf, path->len, exclude,
-			simplify);
+		return treat_directory(dir, untracked, path->buf, path->len,
+				       baselen, exclude, simplify);
 	case DT_REG:
 	case DT_LNK:
 		return exclude ? path_excluded : path_untracked;

@@ -1557,7 +1559,7 @@ static enum path_treatment treat_path(struct dir_struct *dir,
 		return path_none;
 
 	dtype = DTYPE(de);
-	return treat_one_path(dir, untracked, path, simplify, dtype, de);
+	return treat_one_path(dir, untracked, path, baselen, simplify, dtype, de);
 }
 
 static void add_untracked(struct untracked_cache_dir *dir, const char *name)

@@ -1827,7 +1829,7 @@ static int treat_leading_path(struct dir_struct *dir,
 			break;
 		if (simplify_away(sb.buf, sb.len, simplify))
 			break;
-		if (treat_one_path(dir, NULL, &sb, simplify,
+		if (treat_one_path(dir, NULL, &sb, baselen, simplify,
 				   DT_DIR, NULL) == path_none)
 			break; /* do not recurse into it */
 		if (len <= baselen) {

@@ -408,7 +408,8 @@ test_expect_success 'set up sparse checkout' '
 	test_path_is_file done/one
 '
 
-test_expect_success 'create files, some of which are gitignored' '
+test_expect_success 'create/modify files, some of which are gitignored' '
+	echo two bis >done/two &&
 	echo three >done/three && # three is gitignored
 	echo four >done/four && # four is gitignored at a higher level
 	echo five >done/five # five is not gitignored

@@ -420,6 +421,7 @@ test_expect_success 'test sparse status with untracked cache' '
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../status.actual &&
 	cat >../status.expect <<EOF &&
+ M done/two
 ?? .gitignore
 ?? done/five
 ?? dtwo/

@@ -459,6 +461,7 @@ test_expect_success 'test sparse status again with untracked cache' '
 	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
 	git status --porcelain >../status.actual &&
 	cat >../status.expect <<EOF &&
+ M done/two
 ?? .gitignore
 ?? done/five
 ?? dtwo/

@@ -473,4 +476,71 @@ EOF
 	test_cmp ../trace.expect ../trace
 '
 
+test_expect_success 'set up for test of subdir and sparse checkouts' '
+	mkdir done/sub &&
+	mkdir done/sub/sub &&
+	echo "sub" > done/sub/sub/file
+'
+
+test_expect_success 'test sparse status with untracked cache and subdir' '
+	avoid_racy &&
+	: >../trace &&
+	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
+	git status --porcelain >../status.actual &&
+	cat >../status.expect <<EOF &&
+ M done/two
+?? .gitignore
+?? done/five
+?? done/sub/
+?? dtwo/
+EOF
+	test_cmp ../status.expect ../status.actual &&
+	cat >../trace.expect <<EOF &&
+node creation: 2
+gitignore invalidation: 0
+directory invalidation: 1
+opendir: 3
+EOF
+	test_cmp ../trace.expect ../trace
+'
+
+test_expect_success 'verify untracked cache dump (sparse/subdirs)' '
+	test-dump-untracked-cache >../actual &&
+	cat >../expect <<EOF &&
+info/exclude 13263c0978fb9fad16b2d580fb800b6d811c3ff0
+core.excludesfile 0000000000000000000000000000000000000000
+exclude_per_dir .gitignore
+flags 00000006
+/ e6fcc8f2ee31bae321d66afd183fcb7237afae6e recurse valid
+.gitignore
+dtwo/
+/done/ 1946f0437f90c5005533cbe1736a6451ca301714 recurse valid
+five
+sub/
+/done/sub/ 0000000000000000000000000000000000000000 recurse check_only valid
+sub/
+/done/sub/sub/ 0000000000000000000000000000000000000000 recurse check_only valid
+file
+/dthree/ 0000000000000000000000000000000000000000 recurse check_only valid
+/dtwo/ 0000000000000000000000000000000000000000 recurse check_only valid
+two
+EOF
+	test_cmp ../expect ../actual
+'
+
+test_expect_success 'test sparse status again with untracked cache and subdir' '
+	avoid_racy &&
+	: >../trace &&
+	GIT_TRACE_UNTRACKED_STATS="$TRASH_DIRECTORY/trace" \
+	git status --porcelain >../status.actual &&
+	test_cmp ../status.expect ../status.actual &&
+	cat >../trace.expect <<EOF &&
+node creation: 0
+gitignore invalidation: 0
+directory invalidation: 0
+opendir: 0
+EOF
+	test_cmp ../trace.expect ../trace
+'
+
 test_done

@@ -402,7 +402,7 @@ test_expect_success 'set up sparse checkout' '
 	echo "done/[a-z]*" >.git/info/sparse-checkout &&
 	test_config core.sparsecheckout true &&
 	git checkout master &&
-	git update-index --untracked-cache &&
+	git update-index --force-untracked-cache &&
 	git status --porcelain >/dev/null && # prime the cache
 	test_path_is_missing done/.gitignore &&
 	test_path_is_file done/one

@@ -2616,23 +2616,67 @@ done2:
 	return uc;
 }
 
+static void invalidate_one_directory(struct untracked_cache *uc,
+				     struct untracked_cache_dir *ucd)
+{
+	uc->dir_invalidated++;
+	ucd->valid = 0;
+	ucd->untracked_nr = 0;
+}
+
+/*
+ * Normally when an entry is added or removed from a directory,
+ * invalidating that directory is enough. No need to touch its
+ * ancestors. When a directory is shown as "foo/bar/" in git-status
+ * however, deleting or adding an entry may have cascading effect.
+ *
+ * Say the "foo/bar/file" has become untracked, we need to tell the
+ * untracked_cache_dir of "foo" that "bar/" is not an untracked
+ * directory any more (because "bar" is managed by foo as an untracked
+ * "file").
+ *
+ * Similarly, if "foo/bar/file" moves from untracked to tracked and it
+ * was the last untracked entry in the entire "foo", we should show
+ * "foo/" instead. Which means we have to invalidate past "bar" up to
+ * "foo".
+ *
+ * This function traverses all directories from root to leaf. If there
+ * is a chance of one of the above cases happening, we invalidate back
+ * to root. Otherwise we just invalidate the leaf. There may be a more
+ * sophisticated way than checking for SHOW_OTHER_DIRECTORIES to
+ * detect these cases and avoid unnecessary invalidation, for example,
+ * checking for the untracked entry named "bar/" in "foo", but for now
+ * stick to something safe and simple.
+ */
+static int invalidate_one_component(struct untracked_cache *uc,
+				    struct untracked_cache_dir *dir,
+				    const char *path, int len)
+{
+	const char *rest = strchr(path, '/');
+
+	if (rest) {
+		int component_len = rest - path;
+		struct untracked_cache_dir *d =
+			lookup_untracked(uc, dir, path, component_len);
+		int ret =
+			invalidate_one_component(uc, d, rest + 1,
+						 len - (component_len + 1));
+		if (ret)
+			invalidate_one_directory(uc, dir);
+		return ret;
+	}
+
+	invalidate_one_directory(uc, dir);
+	return uc->dir_flags & DIR_SHOW_OTHER_DIRECTORIES;
+}
+
 void untracked_cache_invalidate_path(struct index_state *istate,
 				     const char *path)
 {
-	const char *sep;
-	struct untracked_cache_dir *d;
 	if (!istate->untracked || !istate->untracked->root)
 		return;
-	sep = strrchr(path, '/');
-	if (sep)
-		d = lookup_untracked(istate->untracked,
-				     istate->untracked->root,
-				     path, sep - path);
-	else
-		d = istate->untracked->root;
-	istate->untracked->dir_invalidated++;
-	d->valid = 0;
-	d->untracked_nr = 0;
+	invalidate_one_component(istate->untracked, istate->untracked->root,
+				 path, strlen(path));
 }
 
 void untracked_cache_remove_from_index(struct index_state *istate,

@@ -375,7 +375,7 @@ EOF
 node creation: 0
 gitignore invalidation: 0
 directory invalidation: 0
-opendir: 1
+opendir: 2
 EOF
 	test_cmp ../trace.expect ../trace
 '

@@ -543,4 +543,30 @@ EOF
 	test_cmp ../trace.expect ../trace
 '
 
+test_expect_success 'move entry in subdir from untracked to cached' '
+	git add dtwo/two &&
+	git status --porcelain >../status.actual &&
+	cat >../status.expect <<EOF &&
+ M done/two
+A  dtwo/two
+?? .gitignore
+?? done/five
+?? done/sub/
+EOF
+	test_cmp ../status.expect ../status.actual
+'
+
+test_expect_success 'move entry in subdir from cached to untracked' '
+	git rm --cached dtwo/two &&
+	git status --porcelain >../status.actual &&
+	cat >../status.expect <<EOF &&
+ M done/two
+?? .gitignore
+?? done/five
+?? done/sub/
+?? dtwo/
+EOF
+	test_cmp ../status.expect ../status.actual
+'
+
 test_done