[ot-shape] Enable abvm/blwm features by default

Core Text seems to apply them to Latin text, but Uniscribe doesn’t.

See https://github.com/harfbuzz/harfbuzz/pull/1908#issuecomment-521819343

src/hb-ot-shape-complex-indic.cc

@@ -131,12 +131,6 @@ indic_features[] =
   {HB_TAG('b','l','w','s'), F_GLOBAL_MANUAL_JOINERS},
   {HB_TAG('p','s','t','s'), F_GLOBAL_MANUAL_JOINERS},
   {HB_TAG('h','a','l','n'), F_GLOBAL_MANUAL_JOINERS},
-  /*
-   * Positioning features.
-   * We don't care about the types.
-   */
-  {HB_TAG('a','b','v','m'), F_GLOBAL},
-  {HB_TAG('b','l','w','m'), F_GLOBAL},
 };
 
 /*
@@ -162,9 +156,6 @@ enum {
   _INDIC_PSTS,
   _INDIC_HALN,
 
-  _INDIC_ABVM,
-  _INDIC_BLWM,
-
   INDIC_NUM_FEATURES,
   INDIC_BASIC_FEATURES = INDIC_INIT, /* Don't forget to update this! */
 };

src/hb-ot-shape-complex-khmer.cc

@@ -56,12 +56,6 @@ khmer_features[] =
   {HB_TAG('a','b','v','s'), F_GLOBAL_MANUAL_JOINERS},
   {HB_TAG('b','l','w','s'), F_GLOBAL_MANUAL_JOINERS},
   {HB_TAG('p','s','t','s'), F_GLOBAL_MANUAL_JOINERS},
-  /*
-   * Positioning features.
-   * We don't care about the types.
-   */
-  {HB_TAG('a','b','v','m'), F_GLOBAL},
-  {HB_TAG('b','l','w','m'), F_GLOBAL},
 };
 
 /*
@@ -79,9 +73,6 @@ enum {
   _KHMER_BLWS,
   _KHMER_PSTS,
 
-  _KHMER_ABVM,
-  _KHMER_BLWM,
-
   KHMER_NUM_FEATURES,
   KHMER_BASIC_FEATURES = _KHMER_PRES, /* Don't forget to update this! */
 };

src/hb-ot-shape-complex-myanmar.cc

@@ -59,24 +59,6 @@ myanmar_other_features[] =
   HB_TAG('b','l','w','s'),
   HB_TAG('p','s','t','s'),
 };
-static const hb_tag_t
-myanmar_positioning_features[] =
-{
-  /*
-   * Positioning features.
-   * We don't care about the types.
-   */
-  /* Pre-release version of Windows 8 Myanmar font had abvm,blwm
-   * features.  The released Windows 8 version of the font (as well
-   * as the released spec) used 'mark' instead.  The Windows 8
-   * shaper however didn't apply 'mark' but did apply 'mkmk'.
-   * Perhaps it applied abvm/blwm.  This was fixed in a Windows 8
-   * update, so now it applies mark/mkmk.  We are guessing that
-   * it still applies abvm/blwm too.
-   */
-  HB_TAG('a','b','v','m'),
-  HB_TAG('b','l','w','m'),
-};
 
 static void
 setup_syllables_myanmar (const hb_ot_shape_plan_t *plan,
@@ -113,9 +95,6 @@ collect_features_myanmar (hb_ot_shape_planner_t *plan)
 
   for (unsigned int i = 0; i < ARRAY_LENGTH (myanmar_other_features); i++)
     map->enable_feature (myanmar_other_features[i], F_MANUAL_ZWJ);
-
-  for (unsigned int i = 0; i < ARRAY_LENGTH (myanmar_positioning_features); i++)
-    map->enable_feature (myanmar_positioning_features[i]);
 }
 
 static void

src/hb-ot-shape-complex-use.cc

@@ -88,16 +88,6 @@ use_other_features[] =
   HB_TAG('p','r','e','s'),
   HB_TAG('p','s','t','s'),
 };
-static const hb_tag_t
-use_positioning_features[] =
-{
-  /*
-   * Positioning features.
-   * We don't care about the types.
-   */
-  HB_TAG('a','b','v','m'),
-  HB_TAG('b','l','w','m'),
-};
 
 static void
 setup_syllables_use (const hb_ot_shape_plan_t *plan,
@@ -153,10 +143,6 @@ collect_features_use (hb_ot_shape_planner_t *plan)
   /* "Standard typographic presentation" */
   for (unsigned int i = 0; i < ARRAY_LENGTH (use_other_features); i++)
     map->enable_feature (use_other_features[i], F_MANUAL_ZWJ);
-
-  /* "Positional feature application" */
-  for (unsigned int i = 0; i < ARRAY_LENGTH (use_positioning_features); i++)
-    map->enable_feature (use_positioning_features[i]);
 }
 
 struct use_shape_plan_t

src/hb-ot-shape.cc

@@ -285,6 +285,8 @@ hb_ot_shape_plan_t::position (hb_font_t   *font,
 static const hb_ot_map_feature_t
 common_features[] =
 {
+  {HB_TAG('a','b','v','m'), F_GLOBAL},
+  {HB_TAG('b','l','w','m'), F_GLOBAL},
   {HB_TAG('c','c','m','p'), F_GLOBAL},
   {HB_TAG('l','o','c','l'), F_GLOBAL},
   {HB_TAG('m','a','r','k'), F_GLOBAL_MANUAL_JOINERS},

test/shaping/data/in-house/Makefile.sources

@@ -14,7 +14,6 @@ TESTS = \
 	tests/context-matching.tests \
 	tests/cursive-positioning.tests \
 	tests/default-ignorables.tests \
-	tests/dist.tests \
 	tests/emoji.tests \
 	tests/fallback-positioning.tests \
 	tests/hangul-jamo.tests \
@@ -42,6 +41,7 @@ TESTS = \
 	tests/myanmar-syllable.tests \
 	tests/myanmar-zawgyi.tests \
 	tests/none-directional.tests \
+	tests/positioning-features.tests \
 	tests/rand.tests \
 	tests/spaces.tests \
 	tests/simple.tests \

test/shaping/data/in-house/tests/dist.tests

@@ -1 +0,0 @@
-../fonts/53a91c20e33a596f2be17fb68b382d6b7eb85d5c.ttf::U+0041,U+0056:[A=0+625|V=1+675]

test/shaping/data/in-house/tests/positioning-features.tests

@@ -0,0 +1,3 @@
+../fonts/53a91c20e33a596f2be17fb68b382d6b7eb85d5c.ttf::U+0041,U+0056:[A=0+625|V=1+675]
+../fonts/f79eb71df4e4c9c273b67b89a06e5ff9e3c1f834.ttf::U+006D,U+0315:[m=0+945|uni0315=0@32,-178+0]
+../fonts/ea3f63620511b2097200d23774ffef197e829e69.ttf::U+0079,U+0325:[y=0+565|uni0325=0@-422,-240+0]