master 297c9aa: Fix cursor motion around some Emoji sequences

[Eli Zaretskii]

branch: master
commit 297c9aa3deb64596b7ea19ae7d65a3ae614c7d2f
Author: Eli Zaretskii <eliz@gnu.org>
Commit: Eli Zaretskii <eliz@gnu.org>

    Fix cursor motion around some Emoji sequences
    
    * src/character.h: Add TAG_SPACE and CANCEL_TAG to known Unicode
    characters values.
    * src/composite.c (char_composable_p): Recognize TAG characters
    relevant to Emoji as composable regardless of their General
    Category.  (Bug#39799)
---
 src/character.h | 2 ++
 src/composite.c | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/src/character.h b/src/character.h
index 1a74548..6ee6bca 100644
--- a/src/character.h
+++ b/src/character.h
@@ -82,6 +82,8 @@ enum
   LEFT_ANGLE_BRACKET = 0x3008,
   RIGHT_ANGLE_BRACKET = 0x3009,
   OBJECT_REPLACEMENT_CHARACTER = 0xFFFC,
+  TAG_SPACE = 0xE0020,
+  CANCEL_TAG = 0xE007F,
 };
 
 extern int char_string (unsigned, unsigned char *);
diff --git a/src/composite.c b/src/composite.c
index e97f8e2..c37b1fd 100644
--- a/src/composite.c
+++ b/src/composite.c
@@ -953,6 +953,9 @@ char_composable_p (int c)
   Lisp_Object val;
   return (c >= ' '
          && (c == ZERO_WIDTH_NON_JOINER || c == ZERO_WIDTH_JOINER
+             /* Per Unicode TR51, these tag characters can be part of
+                Emoji sequences.  */
+             || (TAG_SPACE <= c && c <= CANCEL_TAG)
              /* unicode-category-table may not be available during
                 dumping.  */
              || (CHAR_TABLE_P (Vunicode_category_table)