From 1f0149e5a605356f93fd515c19940d1a25c0bb6a Mon Sep 17 00:00:00 2001
From: hanaa12G <ledoanhkhoa123@outlook.com.vn>
Date: Sat, 18 Nov 2023 10:26:46 +0700
Subject: [PATCH] LibLine: Reset state after invalid character in DSR response

While parsing DSR response, we might encounter invalid characters, for
example, when we `cat` a binary file. Previously, we just pushed those
characters in `m_incomplete_data` buffer, which worked fine until we
didn't get a terminating character. We kept increasing coordinate value
and crashed in following assertion.
---
 Userland/Libraries/LibLine/Editor.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Userland/Libraries/LibLine/Editor.cpp b/Userland/Libraries/LibLine/Editor.cpp
index 742732eb1f..4a64d207a2 100644
--- a/Userland/Libraries/LibLine/Editor.cpp
+++ b/Userland/Libraries/LibLine/Editor.cpp
@@ -2128,14 +2128,17 @@ Result<Vector<size_t, 2>, Editor::Error> Editor::vt_dsr()
                 continue;
             }
             m_incomplete_data.append(c);
+            state = Free;
             continue;
         case SawBracket:
             if (is_ascii_digit(c)) {
                 state = InFirstCoordinate;
+                coordinate_buffer.clear_with_capacity();
                 coordinate_buffer.append(c);
                 continue;
             }
             m_incomplete_data.append(c);
+            state = Free;
             continue;
         case InFirstCoordinate:
             if (is_ascii_digit(c)) {
@@ -2152,6 +2155,7 @@ Result<Vector<size_t, 2>, Editor::Error> Editor::vt_dsr()
                 continue;
             }
             m_incomplete_data.append(c);
+            state = Free;
             continue;
         case SawSemicolon:
             if (is_ascii_digit(c)) {
@@ -2160,6 +2164,7 @@ Result<Vector<size_t, 2>, Editor::Error> Editor::vt_dsr()
                 continue;
             }
             m_incomplete_data.append(c);
+            state = Free;
             continue;
         case InSecondCoordinate:
             if (is_ascii_digit(c)) {
@@ -2176,6 +2181,7 @@ Result<Vector<size_t, 2>, Editor::Error> Editor::vt_dsr()
                 continue;
             }
             m_incomplete_data.append(c);
+            state = Free;
             continue;
         case SawR:
             m_incomplete_data.append(c);