From fbfa87d6141b9752f5f7c525a22721583bf46e8c Mon Sep 17 00:00:00 2001
From: Vikram Bhaskaran <vikram.bhaskaran@outlook.com>
Date: Tue, 13 Oct 2026 01:24:02 +1100
Subject: [PATCH] Treat a numeric --connect value as a loopback port.

---
 apps/lightcraft-cli/src/main.rs | 55 +++++++++++++++++++++++++--------
 1 file changed, 42 insertions(+), 13 deletions(-)

diff --git a/apps/lightcraft-cli/src/main.rs b/apps/lightcraft-cli/src/main.rs
index 63a4deb76..e9d8575f6 100644
--- a/apps/lightcraft-cli/src/main.rs
+++ b/apps/lightcraft-cli/src/main.rs
@@ -303,16 +303,16 @@ fn mcp(args: &[String]) -> Result<(), String> {
     while i < args.len() {
         match args[i].as_str() {
             "--connect" => {
-                // Optional address argument.
-                match args.get(i + 1).filter(|a| !a.starts_with("--") && a.contains(':')) {
-                    Some(a) => {
-                        connect = Some(a.clone());
-                        i += 1;
-                    }
-                    None => connect = Some(DEFAULT_ADDR.to_string()),
+                let (addr, took) = connect_value(args.get(i + 1).map(String::as_str));
+                connect = Some(addr);
+                if took {
+                    i += 1;
                 }
             }
-            a if a.starts_with("--connect=") => connect = Some(a["--connect=".len()..].to_string()),
+            a if a.starts_with("--connect=") => {
+                let (addr, _) = connect_value(Some(&a["--connect=".len()..]));
+                connect = Some(addr);
+            }
             "--headless" => connect = None,
             "--demo" => demo = true,
             "--compact" => compact = true,
@@ -525,14 +525,17 @@ fn run(args: &[String]) -> Result<(), String> {
                 i += 1;
                 break;
             }
-            "--connect" => match args.get(i + 1).filter(|a| a.contains(':') && !a.contains('=')) {
-                Some(a) => {
-                    connect = Some(a.clone());
+            "--connect" => {
+                let (addr, took) = connect_value(args.get(i + 1).map(String::as_str));
+                connect = Some(addr);
+                if took {
                     i += 1;
                 }
-                None => connect = Some(DEFAULT_ADDR.to_string()),
             },
-            a if a.starts_with("--connect=") => connect = Some(a["--connect=".len()..].to_string()),
+            a if a.starts_with("--connect=") => {
+                let (addr, _) = connect_value(Some(&a["--connect=".len()..]));
+                connect = Some(addr);
+            }
             "--demo" => demo = true,
             "--library" => library = Some(take_value(args, &mut i, "--library")?.to_string()),
             "--import" => imports.push(take_value(args, &mut i, "--import")?.to_string()),
@@ -627,6 +630,18 @@ fn take_value<'a>(args: &'a [String], i: &mut usize, flag: &str) -> Result<&'a s
 
 /// The port an `--connect` address names, for the recovery hint. The whole address when it has
 /// no port, so a hint is never built from a guess.
+/// `--connect` takes an address, or a bare port (`7980` → `127.0.0.1:7980`). A following
+/// command id is left alone (#1178).
+fn connect_value(next: Option<&str>) -> (String, bool) {
+    match next {
+        Some(a) if !a.starts_with('-') && a.contains(':') && !a.contains('=') => (a.to_string(), true),
+        Some(a) if !a.is_empty() && a.bytes().all(|c| c.is_ascii_digit()) && a.parse::<u16>().ok().is_some_and(|p| p > 0) => {
+            (format!("127.0.0.1:{a}"), true)
+        }
+        _ => (DEFAULT_ADDR.to_string(), false),
+    }
+}
+
 fn connect_port(addr: &str) -> &str {
     addr.rsplit_once(':').map_or(addr, |(_, port)| port)
 }
@@ -965,6 +980,20 @@ fn denoise_serve(args: &[String]) -> Result<(), String> {
     serve(listener, s.model, s.tile, s.device, s.run, opts, std::sync::Arc::new(|m: &str| eprintln!("lightcraft-cli denoise-serve: {m}")))
 }
 
+#[cfg(test)]
+mod connect_tests {
+    use super::connect_value;
+
+    #[test]
+    fn a_bare_port_is_loopback_and_a_command_is_not_consumed() {
+        assert_eq!(connect_value(Some("7980")), ("127.0.0.1:7980".into(), true));
+        assert_eq!(connect_value(Some("127.0.0.1:7980")), ("127.0.0.1:7980".into(), true));
+        assert_eq!(connect_value(Some("photo.rate")), ("127.0.0.1:7980".into(), false));
+        assert_eq!(connect_value(Some("0")), ("127.0.0.1:7980".into(), false));
+        assert_eq!(connect_value(None), ("127.0.0.1:7980".into(), false));
+    }
+}
+
 #[cfg(not(feature = "denoise"))]
 fn denoise_serve(_: &[String]) -> Result<(), String> {
     Err("denoise-serve: this build has no denoise support (build with the `denoise` feature)".into())