1 files changed, 88 insertions, 11 deletions

diff --git a/src/3rdparty/harfbuzz-ng/src/hb-buffer.cc b/src/3rdparty/harfbuzz-ng/src/hb-buffer.cc
index 4b6c2d9eaa..d621a7cc55 100644
--- a/src/3rdparty/harfbuzz-ng/src/hb-buffer.cc
+++ b/src/3rdparty/harfbuzz-ng/src/hb-buffer.cc
@@ -40,6 +40,11 @@
  * Buffers serve a dual role in HarfBuzz; before shaping, they hold
  * the input characters that are passed to hb_shape(), and after
  * shaping they hold the output glyphs.
+ *
+ * The input buffer is a sequence of Unicode codepoints, with
+ * associated attributes such as direction and script.  The output
+ * buffer is a sequence of glyphs, with associated attributes such
+ * as position and cluster.
  **/
 
 
@@ -263,7 +268,7 @@ hb_buffer_t::similar (const hb_buffer_t &src)
   unicode = hb_unicode_funcs_reference (src.unicode);
   flags = src.flags;
   cluster_level = src.cluster_level;
-  replacement = src.invisible;
+  replacement = src.replacement;
   invisible = src.invisible;
   not_found = src.not_found;
 }
@@ -304,6 +309,7 @@ hb_buffer_t::clear ()
 
   deallocate_var_all ();
   serial = 0;
+  random_state = 1;
   scratch_flags = HB_BUFFER_SCRATCH_FLAG_DEFAULT;
 }
 
@@ -494,12 +500,12 @@ hb_buffer_t::set_masks (hb_mask_t    value,
 			unsigned int cluster_start,
 			unsigned int cluster_end)
 {
-  hb_mask_t not_mask = ~mask;
-  value &= mask;
-
   if (!mask)
     return;
 
+  hb_mask_t not_mask = ~mask;
+  value &= mask;
+
   unsigned int count = len;
   for (unsigned int i = 0; i < count; i++)
     if (cluster_start <= info[i].cluster && info[i].cluster < cluster_end)
@@ -522,15 +528,17 @@ hb_buffer_t::merge_clusters_impl (unsigned int start,
     cluster = hb_min (cluster, info[i].cluster);
 
   /* Extend end */
-  while (end < len && info[end - 1].cluster == info[end].cluster)
-    end++;
+  if (cluster != info[end - 1].cluster)
+    while (end < len && info[end - 1].cluster == info[end].cluster)
+      end++;
 
   /* Extend start */
-  while (idx < start && info[start - 1].cluster == info[start].cluster)
-    start--;
+  if (cluster != info[start].cluster)
+    while (idx < start && info[start - 1].cluster == info[start].cluster)
+      start--;
 
   /* If we hit the start of buffer, continue in out-buffer. */
-  if (idx == start)
+  if (idx == start && info[start].cluster != cluster)
     for (unsigned int i = out_len; i && out_info[i - 1].cluster == info[start].cluster; i--)
       set_cluster (out_info[i - 1], cluster);
 
@@ -893,6 +901,32 @@ hb_buffer_get_user_data (const hb_buffer_t  *buffer,
  * Sets the type of @buffer contents. Buffers are either empty, contain
  * characters (before shaping), or contain glyphs (the result of shaping).
  *
+ * You rarely need to call this function, since a number of other
+ * functions transition the content type for you. Namely:
+ *
+ * - A newly created buffer starts with content type
+ *   %HB_BUFFER_CONTENT_TYPE_INVALID. Calling hb_buffer_reset(),
+ *   hb_buffer_clear_contents(), as well as calling hb_buffer_set_length()
+ *   with an argument of zero all set the buffer content type to invalid
+ *   as well.
+ *
+ * - Calling hb_buffer_add_utf8(), hb_buffer_add_utf16(),
+ *   hb_buffer_add_utf32(), hb_buffer_add_codepoints() and
+ *   hb_buffer_add_latin1() expect that buffer is either empty and
+ *   have a content type of invalid, or that buffer content type is
+ *   %HB_BUFFER_CONTENT_TYPE_UNICODE, and they also set the content
+ *   type to Unicode if they added anything to an empty buffer.
+ *
+ * - Finally hb_shape() and hb_shape_full() expect that the buffer
+ *   is either empty and have content type of invalid, or that buffer
+ *   content type is %HB_BUFFER_CONTENT_TYPE_UNICODE, and upon
+ *   success they set the buffer content type to
+ *   %HB_BUFFER_CONTENT_TYPE_GLYPHS.
+ *
+ * The above transitions are designed such that one can use a buffer
+ * in a loop of "reset : add-text : shape" without needing to ever
+ * modify the content type manually.
+ *
  * Since: 0.9.5
  **/
 void
@@ -1294,7 +1328,7 @@ hb_buffer_get_invisible_glyph (const hb_buffer_t *buffer)
  * Sets the #hb_codepoint_t that replaces characters not found in
  * the font during shaping.
  *
- * The not-found glyph defaults to zero, sometimes knows as the
+ * The not-found glyph defaults to zero, sometimes known as the
  * ".notdef" glyph.  This API allows for differentiating the two.
  *
  * Since: 3.1.0
@@ -1326,6 +1360,49 @@ hb_buffer_get_not_found_glyph (const hb_buffer_t *buffer)
   return buffer->not_found;
 }
 
+/**
+ * hb_buffer_set_random_state:
+ * @buffer: An #hb_buffer_t
+ * @state: the new random state
+ *
+ * Sets the random state of the buffer. The state changes
+ * every time a glyph uses randomness (eg. the `rand`
+ * OpenType feature). This function together with
+ * hb_buffer_get_random_state() allow for transferring
+ * the current random state to a subsequent buffer, to
+ * get better randomness distribution.
+ *
+ * Defaults to 1 and when buffer contents are cleared.
+ * A value of 0 disables randomness during shaping.
+ *
+ * Since: 8.4.0
+ **/
+void
+hb_buffer_set_random_state (hb_buffer_t    *buffer,
+			    unsigned        state)
+{
+  if (unlikely (hb_object_is_immutable (buffer)))
+    return;
+
+  buffer->random_state = state;
+}
+
+/**
+ * hb_buffer_get_random_state:
+ * @buffer: An #hb_buffer_t
+ *
+ * See hb_buffer_set_random_state().
+ *
+ * Return value:
+ * The @buffer random state
+ *
+ * Since: 8.4.0
+ **/
+unsigned
+hb_buffer_get_random_state (const hb_buffer_t *buffer)
+{
+  return buffer->random_state;
+}
 
 /**
  * hb_buffer_clear_contents:
@@ -2043,7 +2120,7 @@ hb_buffer_t::sort (unsigned int start, unsigned int end, int(*compar)(const hb_g
  * hb_buffer_diff:
  * @buffer: a buffer.
  * @reference: other buffer to compare to.
- * @dottedcircle_glyph: glyph id of U+25CC DOTTED CIRCLE, or (hb_codepont_t) -1.
+ * @dottedcircle_glyph: glyph id of U+25CC DOTTED CIRCLE, or (hb_codepoint_t) -1.
  * @position_fuzz: allowed absolute difference in position values.
  *
  * If dottedcircle_glyph is (hb_codepoint_t) -1 then #HB_BUFFER_DIFF_FLAG_DOTTED_CIRCLE_PRESENT