fix(terminal): strip C1 control characters (0x80-0x9f) in renderTerminalBufferText (#103274)

lsr911 · claude · steipete · web-flow · commit a3f9f3567f71 · 2026-07-10T06:21:29.000+01:00
renderTerminalBufferText filters C0 control characters (0x00-0x1f) and DEL (0x7f) but did not filter C1 controls (0x80-0x9f). The C1 range includes the CSI (Control Sequence Introducer) at 0x9b, an alternative ANSI escape prefix that stripAnsiSequences() may miss. Add the C1 range to CONTROL_BYTES_REGEX to strip all C1 bytes. Same pattern as the C1 fix in sanitizeForConsole (#103226). Co-authored-by: Claude <noreply@anthropic.com> Co-authored-by: Peter Steinberger <peter@steipete.me>
diff --git a/src/gateway/terminal/buffer-text.ts b/src/gateway/terminal/buffer-text.ts
@@ -6,13 +6,16 @@ import { stripAnsiSequences } from "../../../packages/terminal-core/src/ansi.js"
 // the no-control-regex lint rule cannot statically detect them (same approach
 // as terminal-core's sanitizeForLog). Tab survives; \r/\n are handled above.
 const C0_EXCEPT_TAB_CR_LF = `${String.fromCharCode(0x00)}-${String.fromCharCode(0x08)}${String.fromCharCode(0x0b)}${String.fromCharCode(0x0c)}${String.fromCharCode(0x0e)}-${String.fromCharCode(0x1f)}${String.fromCharCode(0x7f)}`;
-const CONTROL_BYTES_REGEX = new RegExp(`[${C0_EXCEPT_TAB_CR_LF}]`, "g");
+// C1 control characters (0x80-0x9f) include the CSI introducer (0x9b),
+// which is an alternative ANSI escape prefix equivalent to ESC [.
+const C1 = `${String.fromCharCode(0x80)}-${String.fromCharCode(0x9f)}`;
+const CONTROL_BYTES_REGEX = new RegExp(`[${C0_EXCEPT_TAB_CR_LF}${C1}]`, "g");
 
 /**
  * Approximates what a terminal would show without running a VT emulator:
  * strips ANSI sequences, collapses carriage-return overwrites (progress bars
  * emit "10%\r20%\r30%" — keep the last write per line), and drops remaining
- * C0 control bytes. Cursor-movement layouts (vim, htop) will not reconstruct
+ * C0/C1 control bytes. Cursor-movement layouts (vim, htop) will not reconstruct
  * faithfully; a true screen snapshot is a tracked follow-up.
  */
 export function renderTerminalBufferText(raw: string): string {
