From 94e5ad1056372518e56e79229f517963789f0ab9 Mon Sep 17 00:00:00 2001
From: Marco Fontani <mf@marcofontani.it>
Date: Thu, 2 Oct 2025 10:33:51 +0200
Subject: [PATCH] ignore "CSI K" (erase until EOL) sequences

Closes https://github.com/mfontani/ansi2html/issues/37
---
 src/main.c     | 15 +++++++++++++++
 tests/csi-k.sh | 17 +++++++++++++++++
 2 files changed, 32 insertions(+)
 create mode 100755 tests/csi-k.sh

diff --git a/src/main.c b/src/main.c
index 23e9d49..b6f8881 100644
--- a/src/main.c
+++ b/src/main.c
@@ -264,6 +264,11 @@ just_strip_it(bool ignore_sgr_errors)
                 {
                     state = STATE_TEXT;
                 }
+                else if (c == 'K')
+                {
+                    // Ignore "Erase in Line" sequence.
+                    state = STATE_TEXT;
+                }
                 else
                 {
                     if (ignore_sgr_errors)
@@ -519,6 +524,16 @@ static inline __attribute__((always_inline)) void ansi2html(
                     );
                     span_outputted = false;
                 }
+                else if (c == 'K')
+                {
+                    // Ignore "Erase in Line" sequence.
+                    state = STATE_TEXT;
+                    if (span && !span_outputted)
+                    {
+                        append_to_buffer(span);
+                        span_outputted = true;
+                    }
+                }
                 else
                 {
                     // The character should be a digit, or semicolon.
diff --git a/tests/csi-k.sh b/tests/csi-k.sh
new file mode 100755
index 0000000..f7fb9c0
--- /dev/null
+++ b/tests/csi-k.sh
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+set -e
+
+. "$(dirname "$0")/".functions.sh
+
+# CSI K is a no-op when stripping OR converting to HTML
+str=$'Hello, \e[0;1mBold\e[K\e[0m world!'
+want=$'Hello, <span style="font-weight:bold;">Bold</span> world!'
+got=$(printf '%s' "$str" | ./ansi2html -p vga)
+str_eq_html "$str" "$want" "$got"
+
+want=$'Hello, Bold world!'
+got=$(printf '%s' "$str" | ./ansi2html -S)
+str_eq_html "$str" "$want" "$got"
+
+done_testing