font-family settings are repeatable to specify fallback

src/Surface.zig

@@ -342,7 +342,7 @@ pub fn init(
             // A buffer we use to store the font names for logging.
             var name_buf: [256]u8 = undefined;
 
-            if (config.@"font-family") |family| {
+            for (config.@"font-family".list.items) |family| {
                 var disco_it = try disco.discover(alloc, .{
                     .family = family,
                     .style = config.@"font-style".nameValue(),
@@ -364,7 +364,7 @@ pub fn init(
             // a user says `font-style = italic` for the bold face for example,
             // no results would be found if we restrict to ALSO searching for
             // italic.
-            if (config.@"font-family-bold") |family| {
+            for (config.@"font-family-bold".list.items) |family| {
                 const style = config.@"font-style-bold".nameValue();
                 var disco_it = try disco.discover(alloc, .{
                     .family = family,
@@ -379,7 +379,7 @@ pub fn init(
                     _ = try group.addFace(.bold, .{ .deferred = face });
                 } else log.warn("font-family-bold not found: {s}", .{family});
             }
-            if (config.@"font-family-italic") |family| {
+            for (config.@"font-family-italic".list.items) |family| {
                 const style = config.@"font-style-italic".nameValue();
                 var disco_it = try disco.discover(alloc, .{
                     .family = family,
@@ -394,7 +394,7 @@ pub fn init(
                     _ = try group.addFace(.italic, .{ .deferred = face });
                 } else log.warn("font-family-italic not found: {s}", .{family});
             }
-            if (config.@"font-family-bold-italic") |family| {
+            for (config.@"font-family-bold-italic".list.items) |family| {
                 const style = config.@"font-style-bold-italic".nameValue();
                 var disco_it = try disco.discover(alloc, .{
                     .family = family,

src/config/Config.zig

@@ -29,15 +29,21 @@ const c = @cImport({
 });
 
 /// The font families to use.
+///
 /// You can generate the list of valid values using the CLI:
 ///   path/to/ghostty/cli +list-fonts
 ///
+/// This configuration can be repeated multiple times to specify
+/// preferred fallback fonts when the requested codepoint is not
+/// available in the primary font. This is particularly useful for
+/// multiple languages, symbolic fonts, etc.
+///
 /// Changing this configuration at runtime will only affect new terminals,
 /// i.e. new windows, tabs, etc.
-@"font-family": ?[:0]const u8 = null,
-@"font-family-bold": ?[:0]const u8 = null,
-@"font-family-italic": ?[:0]const u8 = null,
-@"font-family-bold-italic": ?[:0]const u8 = null,
+@"font-family": RepeatableString = .{},
+@"font-family-bold": RepeatableString = .{},
+@"font-family-italic": RepeatableString = .{},
+@"font-family-bold-italic": RepeatableString = .{},
 
 /// The named font style to use for each of the requested terminal font
 /// styles. This looks up the style based on the font style string advertised
@@ -1623,15 +1629,15 @@ pub fn finalize(self: *Config) !void {
     // the others to the font family. This way, if someone does
     // --font-family=foo, then we try to get the stylized versions of
     // "foo" as well.
-    if (self.@"font-family") |family| {
+    if (self.@"font-family".count() > 0) {
         const fields = &[_][]const u8{
             "font-family-bold",
             "font-family-italic",
             "font-family-bold-italic",
         };
         inline for (fields) |field| {
-            if (@field(self, field) == null) {
-                @field(self, field) = family;
+            if (@field(self, field).count() == 0) {
+                @field(self, field) = try self.@"font-family".clone(alloc);
             }
         }
     }
@@ -1984,9 +1990,9 @@ test "changed" {
     defer source.deinit();
     var dest = try source.clone(alloc);
     defer dest.deinit();
-    dest.@"font-family" = "something else";
+    dest.@"font-thicken" = true;
 
-    try testing.expect(source.changed(&dest, .@"font-family"));
+    try testing.expect(source.changed(&dest, .@"font-thicken"));
     try testing.expect(!source.changed(&dest, .@"font-size"));
 }
 
@@ -2218,6 +2224,11 @@ pub const RepeatableString = struct {
         };
     }
 
+    /// The number of itemsin the list
+    pub fn count(self: Self) usize {
+        return self.list.items.len;
+    }
+
     /// Compare if two of our value are requal. Required by Config.
     pub fn equal(self: Self, other: Self) bool {
         const itemsA = self.list.items;

src/config/key.zig

@@ -50,6 +50,6 @@ pub fn Value(comptime key: Key) type {
 test "Value" {
     const testing = std.testing;
 
-    try testing.expectEqual(?[:0]const u8, Value(.@"font-family"));
+    try testing.expectEqual(Config.RepeatableString, Value(.@"font-family"));
     try testing.expectEqual(?bool, Value(.@"cursor-style-blink"));
 }