[subset] add --no-layout-closure flag.

Disables layout glyph closure. Fixes #4192.

src/hb-subset-plan.cc

@@ -295,7 +295,7 @@ _closure_glyphs_lookups_features (hb_subset_plan_t   *plan,
                               feature_record_cond_idx_map,
                               feature_substitutes_map);
 
-  if (table_tag == HB_OT_TAG_GSUB)
+  if (table_tag == HB_OT_TAG_GSUB && !(plan->flags & HB_SUBSET_FLAGS_NO_LAYOUT_CLOSURE))
     hb_ot_layout_lookups_substitute_closure (plan->source,
                                              &lookup_indices,
 					     gids_to_retain);

src/hb-subset.h

@@ -71,6 +71,8 @@ typedef struct hb_subset_plan_t hb_subset_plan_t;
  * in the final subset.
  * @HB_SUBSET_FLAGS_NO_PRUNE_UNICODE_RANGES: If set then the unicode ranges in
  * OS/2 will not be recalculated.
+ * @HB_SUBSET_FLAGS_NO_LAYOUT_CLOSURE: If set don't perform glyph closure on layout
+ * tables (GSUB, GPOS, GDEF).
  *
  * List of boolean properties that can be configured on the subset input.
  *
@@ -87,6 +89,7 @@ typedef enum { /*< flags >*/
   HB_SUBSET_FLAGS_NOTDEF_OUTLINE =	     0x00000040u,
   HB_SUBSET_FLAGS_GLYPH_NAMES =		     0x00000080u,
   HB_SUBSET_FLAGS_NO_PRUNE_UNICODE_RANGES =  0x00000100u,
+  HB_SUBSET_FLAGS_NO_LAYOUT_CLOSURE =        0x00000200u,
 } hb_subset_flags_t;
 
 /**

test/subset/data/Makefile.am

@@ -44,6 +44,7 @@ EXTRA_DIST += \
 	expected/layout.duplicate_features \
 	expected/layout.unsorted_featurelist \
 	expected/layout.drop_feature \
+	expected/no_layout_closure \
 	expected/cmap \
 	expected/cmap14 \
 	expected/sbix \

test/subset/data/Makefile.sources

@@ -43,6 +43,7 @@ TESTS = \
 	tests/layout.duplicate_features.tests \
 	tests/layout.unsorted_featurelist.tests \
 	tests/layout.drop_feature.tests \
+	tests/no_layout_closure.tests \
         tests/sbix.tests \
 	tests/variable.tests \
 	tests/glyph_names.tests \

test/subset/data/profiles/no-layout-closure-gids.txt

@@ -0,0 +1,2 @@
+--no-layout-closure
+--gids=74,77,446

test/subset/data/tests/no_layout_closure.tests

@@ -0,0 +1,8 @@
+FONTS:
+Roboto-Regular.ttf
+
+PROFILES:
+no-layout-closure-gids.txt
+
+SUBSETS:
+no-unicodes

test/subset/generate-expected-outputs.py

@@ -47,8 +47,10 @@ def generate_expected_output(input_file, unicodes, profile_flags, instance_flags
 	args.extend(["--drop-tables+=DSIG",
 		     "--drop-tables-=sbix",
 		     "--no-harfbuzz-repacker", # disable harfbuzz repacker so we aren't comparing to ourself.
-		     "--unicodes=%s" % unicodes,
 		     "--output-file=%s" % fonttools_path])
+	if unicodes != "":
+		args.extend(["--unicodes=%s" % unicodes,])
+
 	args.extend(profile_flags)
 	if not no_fonttools:
 		check_call(args)
@@ -63,9 +65,10 @@ def generate_expected_output(input_file, unicodes, profile_flags, instance_flags
 		hb_subset,
 		"--font-file=" + input_file,
 		"--output-file=" + harfbuzz_path,
-		"--unicodes=%s" % unicodes,
 		"--drop-tables+=DSIG",
 		"--drop-tables-=sbix"]
+	if unicodes != "":
+		args.extend(["--unicodes=%s" % unicodes,])
 	args.extend(profile_flags)
 	if instance_flags:
 		args.extend(["--instance=%s" % ','.join(instance_flags)])

test/subset/meson.build

@@ -34,6 +34,7 @@ tests = [
   'layout.duplicate_features',
   'layout.unsorted_featurelist',
   'layout.drop_feature',
+  'no_layout_closure',
   'cmap',
   'cmap14',
   'sbix',

test/subset/subset_test_suite.py

@@ -16,6 +16,8 @@ class Test:
 		import re
 		if self.subset == '*':
 			return self.subset[0]
+		elif self.subset == "no-unicodes":
+			return ""
 		elif re.match("^U\+", self.subset):
 			s = re.sub (r"U\+", "", self.subset)
 			return s
@@ -49,6 +51,11 @@ class Test:
 				       profile_name,
 				       self.instance_name(),
 				       font_base_name_parts[1])
+		elif self.unicodes() == "":
+			return "%s.%s.no-unicodes%s%s" % (font_base_name_parts[0],
+				       profile_name,
+				       self.instance_name(),
+				       font_base_name_parts[1])
 		else:
 			return "%s.%s.%s%s%s" % (font_base_name_parts[0],
 				       profile_name,

util/hb-subset.cc

@@ -941,6 +941,7 @@ subset_main_t::add_options ()
     {"set-overlaps-flag",	0, G_OPTION_FLAG_NO_ARG, G_OPTION_ARG_CALLBACK, (gpointer) &set_flag<HB_SUBSET_FLAGS_SET_OVERLAPS_FLAG>,	"Set the overlaps flag on each glyph.", nullptr},
     {"notdef-outline",		0, G_OPTION_FLAG_NO_ARG, G_OPTION_ARG_CALLBACK, (gpointer) &set_flag<HB_SUBSET_FLAGS_NOTDEF_OUTLINE>,		"Keep the outline of \'.notdef\' glyph", nullptr},
     {"no-prune-unicode-ranges",	0, G_OPTION_FLAG_NO_ARG, G_OPTION_ARG_CALLBACK, (gpointer) &set_flag<HB_SUBSET_FLAGS_NO_PRUNE_UNICODE_RANGES>,	"Don't change the 'OS/2 ulUnicodeRange*' bits.", nullptr},
+    {"no-layout-closure",	0, G_OPTION_FLAG_NO_ARG, G_OPTION_ARG_CALLBACK, (gpointer) &set_flag<HB_SUBSET_FLAGS_NO_LAYOUT_CLOSURE>,	"Don't perform glyph closure for layout tables (GSUB, GPOS, GDEF).", nullptr},
     {"glyph-names",		0, G_OPTION_FLAG_NO_ARG, G_OPTION_ARG_CALLBACK, (gpointer) &set_flag<HB_SUBSET_FLAGS_GLYPH_NAMES>,		"Keep PS glyph names in TT-flavored fonts. ", nullptr},
     {"passthrough-tables",	0, G_OPTION_FLAG_NO_ARG, G_OPTION_ARG_CALLBACK, (gpointer) &set_flag<HB_SUBSET_FLAGS_PASSTHROUGH_UNRECOGNIZED>,	"Do not drop tables that the tool does not know how to subset.", nullptr},
     {"preprocess-face",		0, G_OPTION_FLAG_HIDDEN, G_OPTION_ARG_NONE, &this->preprocess,