Remove guessed_emoji_width

Just guess anew when it's not set.

(this still uses the value of $fish_emoji_width, but clamped to 1 or 2
- we could also guess if it's an unusable value, but that's a
different issue and tbh this variable is becoming less and less useful
as time moves on and things move to the new widths by default)

Fixes #8274.

src/env_dispatch.cpp

@@ -149,11 +149,11 @@ static void handle_timezone(const wchar_t *env_var_name, const environment_t &va
     tzset();
 }
 
-/// Update the value of g_guessed_fish_emoji_width
+/// Update the value of g_fish_emoji_width
 static void guess_emoji_width(const environment_t &vars) {
     if (auto width_str = vars.get(L"fish_emoji_width")) {
         int new_width = fish_wcstol(width_str->as_string().c_str());
-        g_fish_emoji_width = std::max(0, new_width);
+        g_fish_emoji_width = std::min(2,std::max(1, new_width));
         FLOGF(term_support, "'fish_emoji_width' preference: %d, overwriting default",
               g_fish_emoji_width);
         return;
@@ -172,18 +172,18 @@ static void guess_emoji_width(const environment_t &vars) {
 
     if (term == L"Apple_Terminal" && version >= 400) {
         // Apple Terminal on High Sierra
-        g_guessed_fish_emoji_width = 2;
+        g_fish_emoji_width = 2;
         FLOGF(term_support, "default emoji width: 2 for %ls", term.c_str());
     } else if (term == L"iTerm.app") {
         // iTerm2 now defaults to Unicode 9 sizes for anything after macOS 10.12.
-        g_guessed_fish_emoji_width = 2;
+        g_fish_emoji_width = 2;
         FLOGF(term_support, "default emoji width for iTerm: 2");
     } else {
         // Default to whatever system wcwidth says to U+1F603,
-        // but only if it's at least 1.
+        // but only if it's at least 1 and at most 2.
         int w = wcwidth(L'😃');
-        g_guessed_fish_emoji_width = w > 0 ? w : 1;
-        FLOGF(term_support, "default emoji width: %d", g_guessed_fish_emoji_width);
+        g_fish_emoji_width = std::min(2,std::max(1, w));
+        FLOGF(term_support, "default emoji width: %d", g_fish_emoji_width);
     }
 }
 

src/fallback.cpp

@@ -221,17 +221,12 @@ int killpg(int pgr, int sig) {
 int g_fish_ambiguous_width = 1;
 
 // Width of emoji characters.
-int g_fish_emoji_width = 0;
-
 // 1 is the typical emoji width in Unicode 8.
-int g_guessed_fish_emoji_width = 1;
+int g_fish_emoji_width = 1;
 
 static int fish_get_emoji_width(wchar_t c) {
     (void)c;
-    // Respect an explicit value. If we don't have one, use the guessed value. Do not try to fall
-    // back to wcwidth(), it's hopeless.
-    if (g_fish_emoji_width > 0) return g_fish_emoji_width;
-    return g_guessed_fish_emoji_width;
+    return g_fish_emoji_width;
 }
 
 // Big hack to use our versions of wcswidth where we know them to be broken, which is

src/fallback.h

@@ -21,9 +21,6 @@ extern int g_fish_ambiguous_width;
 /// painful this is. A value of 0 means to use the guessed value.
 extern int g_fish_emoji_width;
 
-/// The guessed value of the emoji width based on TERM.
-extern int g_guessed_fish_emoji_width;
-
 /// fish's internal versions of wcwidth and wcswidth, which can use an internal implementation if
 /// the system one is busted.
 int fish_wcwidth(wchar_t wc);