Merge branch 'feature/upstream' into develop

1 files changed, 41 insertions, 42 deletions

diff --git a/lib/unigbrk/u-grapheme-breaks.h b/lib/unigbrk/u-grapheme-breaks.h
index 48afcd6..e1b600f 100644
--- a/lib/unigbrk/u-grapheme-breaks.h
+++ b/lib/unigbrk/u-grapheme-breaks.h
@@ -1,28 +1,30 @@
 /* Grapheme cluster break function.
-   Copyright (C) 2010-2018 Free Software Foundation, Inc.
+   Copyright (C) 2010-2022 Free Software Foundation, Inc.
    Written by Ben Pfaff <blp@cs.stanford.edu>, 2010.
 
-   This program is free software: you can redistribute it and/or
-   modify it under the terms of either:
-
-     * the GNU Lesser General Public License as published by the Free
-       Software Foundation; either version 3 of the License, or (at your
-       option) any later version.
-
-   or
-
-     * the GNU General Public License as published by the Free
-       Software Foundation; either version 2 of the License, or (at your
-       option) any later version.
-
-   or both in parallel, as here.
-   This program is distributed in the hope that it will be useful,
+   This file is free software.
+   It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+".
+   You can redistribute it and/or modify it under either
+     - the terms of the GNU Lesser General Public License as published
+       by the Free Software Foundation; either version 3, or (at your
+       option) any later version, or
+     - the terms of the GNU General Public License as published by the
+       Free Software Foundation; either version 2, or (at your option)
+       any later version, or
+     - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+".
+
+   This file is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
+   Lesser General Public License and the GNU General Public License
+   for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License and of the GNU General Public License along with this
+   program.  If not, see <https://www.gnu.org/licenses/>.  */
 
-   You should have received a copy of the GNU Lesser General Public License
-   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+/* This file implements section 3 "Grapheme Cluster Boundaries"
+   of Unicode Standard Annex #29 <https://www.unicode.org/reports/tr29/>.  */
 
 void
 FUNC (const UNIT *s, size_t n, char *p)
@@ -35,10 +37,15 @@ FUNC (const UNIT *s, size_t n, char *p)
          -1 at the very beginning of the string.  */
       int last_char_prop = -1;
 
-      /* Grapheme Cluster break property of the last complex character.
-         -1 at the very beginning of the string.  */
-      int last_compchar_prop = -1;
+      /* True if the last character ends an emoji modifier sequence
+         \p{Extended_Pictographic} Extend*.  */
+      bool emoji_modifier_sequence = false;
+      /* True if the last character was immediately preceded by an
+         emoji modifier sequence   \p{Extended_Pictographic} Extend*.  */
+      bool emoji_modifier_sequence_before_last_char = false;
 
+      /* Number of consecutive regional indicator (RI) characters seen
+         immediately before the current point.  */
       size_t ri_count = 0;
 
       /* Don't break inside multibyte characters.  */
@@ -89,35 +96,27 @@ FUNC (const UNIT *s, size_t n, char *p)
               /* No break after Prepend characters (GB9b).  */
               else if (last_char_prop == GBP_PREPEND)
                 /* *p = 0 */;
-              /* No break within emoji modifier sequences (GB10).  */
-              else if ((last_compchar_prop == GBP_EB
-                        || last_compchar_prop == GBP_EBG)
-                       && prop == GBP_EM)
-                /* *p = 0 */;
-              /* No break within emoji zwj sequences (GB11).  */
+              /* No break within emoji modifier sequences or emoji zwj sequences
+                 (GB11).  */
               else if (last_char_prop == GBP_ZWJ
-                       && (prop == GBP_GAZ
-                           || prop == GBP_EBG))
+                       && emoji_modifier_sequence_before_last_char
+                       && uc_is_property_extended_pictographic (uc))
                 /* *p = 0 */;
               /* No break between RI if there is an odd number of RI
                  characters before (GB12, GB13).  */
-              else if (prop == GBP_RI)
-                {
-                  if (ri_count % 2 == 0)
-                    *p = 1;
-                  /* else *p = 0; */
-                }
-              /* Break everywhere (GBP999).  */
+              else if (prop == GBP_RI && (ri_count % 2) != 0)
+                /* *p = 0 */;
+              /* Break everywhere (GB999).  */
               else
                 *p = 1;
             }
 
-          last_char_prop = prop;
+          emoji_modifier_sequence_before_last_char = emoji_modifier_sequence;
+          emoji_modifier_sequence =
+            (emoji_modifier_sequence && prop == GBP_EXTEND)
+            || uc_is_property_extended_pictographic (uc);
 
-          if (!(prop == GBP_EXTEND
-                && (last_compchar_prop == GBP_EB
-                    || last_compchar_prop == GBP_EBG)))
-            last_compchar_prop = prop;
+          last_char_prop = prop;
 
           if (prop == GBP_RI)
             ri_count++;