Treat Fitzpatrick emoji modifiers as width 0

Fixes #8275

CHANGELOG.rst

@@ -108,7 +108,8 @@ Improved terminal support
 - Dynamic terminal titles are enabled on WezTerm (:issue:`8121`).
 - Directory history navigation works out of the box with Apple Terminal's default key settings (:issue:`2330`).
 - fish now assumes Unicode 9+ widths for emoji under iTerm 2 (:issue:`8200`).
-- fish's escape sequence removal now also knows Tmux' wrapped escapes.
+- Skin-tone emoji modifiers (U+1F3FB through U+1F3FF) are now measured as width 0 (:issue:`8275`).
+- fish's escape sequence removal now also knows Tmux's wrapped escapes.
 
 Other improvements
 ------------------------------

src/fallback.cpp

@@ -260,6 +260,12 @@ int fish_wcwidth(wchar_t wc) {
     // or standalone with a 1 width. Since that's literally not expressible with wcwidth(),
     // we take the position that the typical way for them to show up is composed.
     if (wc >= L'\u1160' && wc <= L'\u11FF') return 0;
+
+    // Check for Emoji_Modifier property. Only the Fitzpatrick modifiers have this, in range
+    // 1F3FB..1F3FF. This is a hack because such an emoji appearing on its own would be drawn as
+    // width 2, but that's unlikely to be useful. See #8275.
+    if (wc >= 0x1F3FB && wc <= 0x1F3FF) return 0;
+
     int width = widechar_wcwidth(wc);
 
     switch (width) {