Fix three-byte escape sequences leaking final byte into history

cursoragent · cursoragent · commit 87caa1b78f50 · 2026-03-24T17:02:14.000Z
Handle ECMA-48 escape sequences with intermediate bytes (0x20-0x2F)
such as ESC ( B (select ASCII for G0), ESC ) 0 (select DEC Special
Graphics for G1), and ESC # 8 (DECALN). These are commonly emitted by
ncurses programs (vim, less, htop) on exit. Previously only 2 bytes
were consumed, causing the final byte to leak into visibleText.
diff --git a/apps/server/src/terminal/Layers/Manager.ts b/apps/server/src/terminal/Layers/Manager.ts
@@ -321,6 +321,22 @@ function sanitizeTerminalHistoryChunk(
         continue;
       }
 
+      if (nextCodePoint >= 0x20 && nextCodePoint <= 0x2f) {
+        let cursor = index + 2;
+        while (
+          cursor < input.length &&
+          input.charCodeAt(cursor) >= 0x20 &&
+          input.charCodeAt(cursor) <= 0x2f
+        ) {
+          cursor++;
+        }
+        if (cursor >= input.length) {
+          return { visibleText, pendingControlSequence: input.slice(index) };
+        }
+        index = cursor + 1;
+        continue;
+      }
+
       index += 2;
       continue;
     }
