From a003890e8462b001cc522e0d7785fd4248c8365f Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Sat, 21 Sep 2024 11:30:56 -0600
Subject: [PATCH] [buffer] Add
 hb_buffer_[sg]et_not_found_variation_selector_glyph()

Unused.
---
 src/hb-buffer.cc             | 41 ++++++++++++++++++++++++++++++++++++
 src/hb-buffer.h              |  7 ++++++
 src/hb-buffer.hh             |  1 +
 src/hb-ot-shape-normalize.cc |  7 +++---
 src/hb-ot-shape-normalize.hh |  1 -
 5 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/src/hb-buffer.cc b/src/hb-buffer.cc
index d621a7cc5..b7be00ea4 100644
--- a/src/hb-buffer.cc
+++ b/src/hb-buffer.cc
@@ -271,6 +271,7 @@ hb_buffer_t::similar (const hb_buffer_t &src)
   replacement = src.replacement;
   invisible = src.invisible;
   not_found = src.not_found;
+  not_found_variation_selector = src.not_found_variation_selector;
 }
 
 void
@@ -283,6 +284,7 @@ hb_buffer_t::reset ()
   replacement = HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT;
   invisible = 0;
   not_found = 0;
+  not_found_variation_selector = HB_CODEPOINT_INVALID;
 
   clear ();
 }
@@ -705,6 +707,7 @@ DEFINE_NULL_INSTANCE (hb_buffer_t) =
   HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT,
   0, /* invisible */
   0, /* not_found */
+  HB_CODEPOINT_INVALID, /* not_found_variation_selector */
 
 
   HB_BUFFER_CONTENT_TYPE_INVALID,
@@ -1360,6 +1363,44 @@ hb_buffer_get_not_found_glyph (const hb_buffer_t *buffer)
   return buffer->not_found;
 }
 
+/**
+ * hb_buffer_set_not_found_variation_selector_glyph:
+ * @buffer: An #hb_buffer_t
+ * @not_found_variation_selector: the not-found-variation-selector #hb_codepoint_t
+ *
+ * Sets the #hb_codepoint_t that replaces variation-selector characters not resolved
+ * in the font during shaping.
+ *
+ * The not-found-variation-selector glyph defaults to #HB_CODEPOINT_INVALID,
+ * in which case it will be removed from the glyph string during shaping.
+ * This API allows for changing that and retaining the glyph.
+ *
+ * XSince: REPLACEME
+ **/
+void
+hb_buffer_set_not_found_variation_selector_glyph (hb_buffer_t    *buffer,
+						  hb_codepoint_t  not_found_variation_selector)
+{
+  buffer->not_found_variation_selector = not_found_variation_selector;
+}
+
+/**
+ * hb_buffer_get_not_found_variation_selector_glyph:
+ * @buffer: An #hb_buffer_t
+ *
+ * See hb_buffer_set_not_found_variation_selector_glyph().
+ *
+ * Return value:
+ * The @buffer not-found-variation-selector #hb_codepoint_t
+ *
+ * XSince: REPLACEME
+ **/
+hb_codepoint_t
+hb_buffer_get_not_found_variation_selector_glyph (const hb_buffer_t *buffer)
+{
+  return buffer->not_found_variation_selector;
+}
+
 /**
  * hb_buffer_set_random_state:
  * @buffer: An #hb_buffer_t
diff --git a/src/hb-buffer.h b/src/hb-buffer.h
index f75fe96b2..dd0edb9b7 100644
--- a/src/hb-buffer.h
+++ b/src/hb-buffer.h
@@ -487,6 +487,13 @@ hb_buffer_set_not_found_glyph (hb_buffer_t    *buffer,
 HB_EXTERN hb_codepoint_t
 hb_buffer_get_not_found_glyph (const hb_buffer_t *buffer);
 
+HB_EXTERN void
+hb_buffer_set_not_found_variation_selector_glyph (hb_buffer_t    *buffer,
+						  hb_codepoint_t  not_found_variation_selector);
+
+HB_EXTERN hb_codepoint_t
+hb_buffer_get_not_found_variation_selector_glyph (const hb_buffer_t *buffer);
+
 HB_EXTERN void
 hb_buffer_set_random_state (hb_buffer_t    *buffer,
 			    unsigned        state);
diff --git a/src/hb-buffer.hh b/src/hb-buffer.hh
index 0a198722d..abf87e7a6 100644
--- a/src/hb-buffer.hh
+++ b/src/hb-buffer.hh
@@ -80,6 +80,7 @@ struct hb_buffer_t
   hb_codepoint_t replacement; /* U+FFFD or something else. */
   hb_codepoint_t invisible; /* 0 or something else. */
   hb_codepoint_t not_found; /* 0 or something else. */
+  hb_codepoint_t not_found_variation_selector; /* HB_CODEPOINT_INVALID or something else. */
 
   /*
    * Buffer contents
diff --git a/src/hb-ot-shape-normalize.cc b/src/hb-ot-shape-normalize.cc
index 7948899ab..4da711c85 100644
--- a/src/hb-ot-shape-normalize.cc
+++ b/src/hb-ot-shape-normalize.cc
@@ -153,7 +153,7 @@ decompose_current_character (const hb_ot_shape_normalize_context_t *c, bool shor
   hb_codepoint_t u = buffer->cur().codepoint;
   hb_codepoint_t glyph = 0;
 
-  if (shortest && c->font->get_nominal_glyph (u, &glyph, c->not_found))
+  if (shortest && c->font->get_nominal_glyph (u, &glyph, buffer->not_found))
   {
     next_char (buffer, glyph);
     return;
@@ -165,7 +165,7 @@ decompose_current_character (const hb_ot_shape_normalize_context_t *c, bool shor
     return;
   }
 
-  if (!shortest && c->font->get_nominal_glyph (u, &glyph, c->not_found))
+  if (!shortest && c->font->get_nominal_glyph (u, &glyph, buffer->not_found))
   {
     next_char (buffer, glyph);
     return;
@@ -295,7 +295,8 @@ _hb_ot_shape_normalize (const hb_ot_shape_plan_t *plan,
     buffer,
     font,
     buffer->unicode,
-    buffer->not_found,
+    plan->shaper->decompose ? plan->shaper->decompose : hb_ot_shape_normalize_context_t::decompose_unicode,
+    plan->shaper->compose   ? plan->shaper->compose   : hb_ot_shape_normalize_context_t::compose_unicode
   };
   c.override_decompose_and_compose (plan->shaper->decompose, plan->shaper->compose);
 
diff --git a/src/hb-ot-shape-normalize.hh b/src/hb-ot-shape-normalize.hh
index 0e8a54b60..f12cb35c0 100644
--- a/src/hb-ot-shape-normalize.hh
+++ b/src/hb-ot-shape-normalize.hh
@@ -89,7 +89,6 @@ struct hb_ot_shape_normalize_context_t
   hb_buffer_t *buffer;
   hb_font_t *font;
   hb_unicode_funcs_t *unicode;
-  const hb_codepoint_t not_found;
   bool (*decompose) (const hb_ot_shape_normalize_context_t *c,
 		     hb_codepoint_t  ab,
 		     hb_codepoint_t *a,