From e8b19e08fa5f035b7407b41b1fbc7ccc1b700234 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Wed, 5 Jan 2022 22:33:53 +0530
Subject: [PATCH] Fix non-renderable combining chars causing some text to not
 be rendered on Linux

The test for non-renderable chars was broken and the variation selectors
were not included in the test. Fixes #4444
---
 docs/changelog.rst   | 3 +++
 gen-wcwidth.py       | 2 +-
 kitty/fonts.c        | 3 ++-
 kitty/unicode-data.c | 4 +++-
 4 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/docs/changelog.rst b/docs/changelog.rst
index d6579531e..e2c36b662 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -86,6 +86,9 @@ Detailed list of changes
 - Fix showing debug information not working if kitty's :file:`STDIN` is not a tty
   (:iss:`4424`)
 
+- Linux: Fix a regression that broke rendering of emoji with variation selectors
+  (:iss:`4444`)
+
 
 0.24.0 [2022-01-04]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/gen-wcwidth.py b/gen-wcwidth.py
index aeeab712c..09f4b9a66 100755
--- a/gen-wcwidth.py
+++ b/gen-wcwidth.py
@@ -388,7 +388,7 @@ def gen_ucd() -> None:
         category_test(
             'is_non_rendered_char', p, 'Cc Cs Cf'.split(),
             'Other_Default_Ignorable_Code_Point and soft hyphen',
-            extra_chars=property_maps['Other_Default_Ignorable_Code_Point'],
+            extra_chars=property_maps['Other_Default_Ignorable_Code_Point'] | set(range(0xfe00, 0xfe0f + 1)),
             ascii_range='false'
         )
         category_test('is_word_char', p, {c for c in class_maps if c[0] in 'LN'}, 'L and N categories')
diff --git a/kitty/fonts.c b/kitty/fonts.c
index c6b0f1328..49c903fe7 100644
--- a/kitty/fonts.c
+++ b/kitty/fonts.c
@@ -387,7 +387,8 @@ has_cell_text(Font *self, CPUCell *cell) {
     char_type combining_chars[arraysz(cell->cc_idx)];
     unsigned num_cc = 0;
     for (unsigned i = 0; i < arraysz(cell->cc_idx) && cell->cc_idx[i]; i++) {
-        if (!is_non_rendered_char(cell->cc_idx[i])) combining_chars[num_cc++] = codepoint_for_mark(cell->cc_idx[i]);
+        const char_type ccp = codepoint_for_mark(cell->cc_idx[i]);
+        if (!is_non_rendered_char(ccp)) combining_chars[num_cc++] = ccp;
     }
     if (num_cc == 0) return true;
     if (num_cc == 1) {
diff --git a/kitty/unicode-data.c b/kitty/unicode-data.c
index 1e6b41dc9..16b1fd7a9 100644
--- a/kitty/unicode-data.c
+++ b/kitty/unicode-data.c
@@ -699,7 +699,7 @@ is_ignored_char(char_type code) {
 
 bool
 is_non_rendered_char(char_type code) {
-	// Other_Default_Ignorable_Code_Point and soft hyphen (6052 codepoints) {{{
+	// Other_Default_Ignorable_Code_Point and soft hyphen (6068 codepoints) {{{
 	if (LIKELY(0x20 <= code && code <= 0x7e)) return false;
 	switch(code) {
 		case 0x0 ... 0x1f:
@@ -738,6 +738,8 @@ is_non_rendered_char(char_type code) {
 			return true;
 		case 0xd800 ... 0xdfff:
 			return true;
+		case 0xfe00 ... 0xfe0f:
+			return true;
 		case 0xfeff:
 			return true;
 		case 0xffa0: