From a670460db40cf802c9ffad4b3328dd8a5df2410c Mon Sep 17 00:00:00 2001
From: Matias Palma <matiaspalma2594@gmail.com>
Date: Sat, 18 Apr 2026 22:07:34 -0400
Subject: [PATCH] fix: spawn pty with actual terminal size to avoid initial
 reflow

---
 apps/desktop/src-tauri/src/pty.rs        |  6 ++++--
 apps/desktop/src/api/tauri.ts            |  2 +-
 apps/desktop/src/components/Terminal.tsx | 21 ++++++++++++++++++---
 3 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/apps/desktop/src-tauri/src/pty.rs b/apps/desktop/src-tauri/src/pty.rs
index d367aaec..f6078f12 100644
--- a/apps/desktop/src-tauri/src/pty.rs
+++ b/apps/desktop/src-tauri/src/pty.rs
@@ -16,6 +16,8 @@ pub fn spawn_pty<R: Runtime>(
     app: AppHandle<R>,
     state: tauri::State<'_, Arc<Mutex<Option<PtyState>>>>,
     cwd: Option<String>,
+    rows: Option<u16>,
+    cols: Option<u16>,
 ) -> Result<(), String> {
     // If session exists, it will be replaced (dropping old resources kills the previous PTY)
 
@@ -51,8 +53,8 @@ pub fn spawn_pty<R: Runtime>(
 
     let pair = pty_system
         .openpty(PtySize {
-            rows: 24,
-            cols: 80,
+            rows: rows.unwrap_or(24),
+            cols: cols.unwrap_or(80),
             pixel_width: 0,
             pixel_height: 0,
         })
diff --git a/apps/desktop/src/api/tauri.ts b/apps/desktop/src/api/tauri.ts
index 3bee5584..c24afe88 100644
--- a/apps/desktop/src/api/tauri.ts
+++ b/apps/desktop/src/api/tauri.ts
@@ -43,7 +43,7 @@ export interface TauriInvokeMap {
   "ollama_proxy": { args: { method: string; url: string; body: OllamaRequest }; return: { status: number; body: string } };
   "check_update": { args: { url: string }; return: { version: string; body?: string | null } | null };
   "install_update": { args: { url: string }; return: void };
-  "spawn_pty": { args: { cwd?: string }; return: void };
+  "spawn_pty": { args: { cwd?: string; rows?: number; cols?: number }; return: void };
   "write_to_pty": { args: { data: string }; return: void };
   "resize_pty": { args: { rows: number; cols: number }; return: void };
   "kill_pty": { args: undefined; return: void };
diff --git a/apps/desktop/src/components/Terminal.tsx b/apps/desktop/src/components/Terminal.tsx
index 2a2dcbec..49d2be3b 100644
--- a/apps/desktop/src/components/Terminal.tsx
+++ b/apps/desktop/src/components/Terminal.tsx
@@ -14,6 +14,7 @@ const Terminal: React.FC = () => {
   const { t } = useL10n();
   const terminalRef = useRef<HTMLDivElement>(null);
   const xtermRef = useRef<Xterm | null>(null);
+  const fitAddonRef = useRef<FitAddon | null>(null);
   const initialized = useRef(false);
   const activePtyPath = useRef<string | null | undefined>(undefined); // tracks last spawned path
 
@@ -59,6 +60,7 @@ const Terminal: React.FC = () => {
     term.loadAddon(fitAddon);
     term.open(terminalRef.current);
     xtermRef.current = term;
+    fitAddonRef.current = fitAddon;
 
     term.onData((data) => {
       invoke("write_to_pty", { data }).catch(e => console.error("PTY write error:", e));
@@ -85,6 +87,7 @@ const Terminal: React.FC = () => {
       resizeObserver.disconnect();
       term.dispose();
       xtermRef.current = null;
+      fitAddonRef.current = null;
     };
   }, []);
 
@@ -111,14 +114,26 @@ const Terminal: React.FC = () => {
             xtermRef.current.write(event.payload);
           }
         });
-        
+
         if (isCanceled) {
           u();
           return;
         }
-        
+
         unlisten = u;
-        await invoke("spawn_pty", { cwd: targetPath });
+
+        // Fit the terminal to its container before spawning so the shell
+        // starts with the correct rows/cols and avoids a reflow on the first prompt.
+        const term = xtermRef.current;
+        if (term && fitAddonRef.current && terminalRef.current?.clientWidth) {
+          fitAddonRef.current.fit();
+        }
+
+        await invoke("spawn_pty", {
+          cwd: targetPath,
+          rows: term?.rows,
+          cols: term?.cols,
+        });
       } catch (err) {
         if (!isCanceled && xtermRef.current) {
           xtermRef.current.writeln("\x1b[31m" + t('terminal.error_connect') + "\x1b[0m " + err);