terminal: ignore invalid C0 escape codes

src/terminal/ansi.zig

@@ -23,6 +23,10 @@ pub const C0 = enum(u7) {
     SO = 0x0E,
     /// Shift in
     SI = 0x0F,
+
+    // Non-exhaustive so that @intToEnum never fails since the inputs are
+    // user-generated.
+    _,
 };
 
 /// The SGR rendition aspects that can be set, sometimes known as attributes.

src/terminal/stream.zig

@@ -73,7 +73,6 @@ pub fn Stream(comptime Handler: type) type {
             tracy.value(@intCast(u64, c));
             defer tracy.end();
 
-            // log.warn("C0: {}", .{c});
             switch (@intToEnum(ansi.C0, c)) {
                 .NUL => {},
 
@@ -122,6 +121,8 @@ pub fn Stream(comptime Handler: type) type {
                     try self.handler.invokeCharset(.GL, .G0, false)
                 else
                     log.warn("unimplemented invokeCharset: {x}", .{c}),
+
+                else => log.warn("invalid C0 character, ignoring: {x}", .{c}),
             }
         }