default disable kitty graphics until support is improved

You can run `wezterm --config enable_kitty_graphics=true` to do ad-hoc
tests with the protocol enabled.

refs: #986
refs: #1998

config/src/lib.rs

@@ -791,6 +791,10 @@ pub struct Config {
     #[serde(default = "default_initial_rows")]
     pub initial_rows: u16,
 
+    /// Disabled by default until the implementation is complete enough
+    #[serde(default)]
+    pub enable_kitty_graphics: bool,
+
     /// Specifies the width of a new window, expressed in character cells
     #[serde(default = "default_initial_cols")]
     pub initial_cols: u16,

config/src/terminal.rs

@@ -66,4 +66,8 @@ impl wezterm_term::TerminalConfiguration for TermConfig {
     fn enq_answerback(&self) -> String {
         configuration().enq_answerback.clone()
     }
+
+    fn enable_kitty_graphics(&self) -> bool {
+        self.configuration().enable_kitty_graphics
+    }
 }

term/src/config.rs

@@ -76,4 +76,8 @@ pub trait TerminalConfiguration: std::fmt::Debug {
     fn enq_answerback(&self) -> String {
         "".to_string()
     }
+
+    fn enable_kitty_graphics(&self) -> bool {
+        false
+    }
 }

term/src/terminalstate.rs

@@ -1801,6 +1801,9 @@ impl TerminalState {
     }
 
     fn kitty_img(&mut self, img: KittyImage) -> anyhow::Result<()> {
+        if !self.config.enable_kitty_graphics() {
+            return Ok(());
+        }
         match img {
             KittyImage::TransmitData {
                 transmit,