From 4595841b32d8a3782a00ac7c1cd0ceaadb8bd567 Mon Sep 17 00:00:00 2001
From: ragnarok-clanker <ragnarok-clanker>
Date: Wed, 28 Oct 2026 12:36:28 +0000
Subject: [PATCH] Decompile fn_17789 (TextInputBuffer::AdvanceCursor)

Batch #1387 by ragnarok-clanker: 0 byte-identical, 1 confirmed by peer review.

- fn_17789 TextInputBuffer::AdvanceCursor: logic confirmed by peer review

Peer-reviewed-by: Yommy
Reviewed-by: ragnarok-clanker
---
 Source/Client/Input/TextInputBuffer.cpp | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/Source/Client/Input/TextInputBuffer.cpp b/Source/Client/Input/TextInputBuffer.cpp
index 01cd21d5..d7e6cb83 100644
--- a/Source/Client/Input/TextInputBuffer.cpp
+++ b/Source/Client/Input/TextInputBuffer.cpp
@@ -209,8 +209,27 @@ void TextInputBuffer::MoveForward(unsigned codePage) {
     this->cursor = static_cast<int>(CharNextExA(static_cast<WORD>(codePage), begin + position, 0) - begin);
   }
 }
-
 // OFFSET: 0x00ACE5E0
+// FUNCTION: fn_17789
+void TextInputBuffer::AdvanceCursor(int delta) {
+  const unsigned length = static_cast<unsigned>(this->text.size());
+  unsigned cursor = static_cast<unsigned>(this->cursor);
+  if (cursor == length) {
+    return;
+  }
+  if (cursor > length) {
+    this->cursor = static_cast<int>(length);
+  } else {
+    unsigned next = cursor + static_cast<unsigned>(delta);
+    if (next <= length) {
+      this->cursor = static_cast<int>(next);
+    }
+  }
+  if ((static_cast<unsigned short>(GetKeyState(VK_SHIFT)) >> 8) == 0) {
+    this->anchor = this->cursor;
+  }
+}
+
 // OFFSET: 0x00ACE620
 // FUNCTION: fn_17790
 void TextInputBuffer::RetreatCursor(int delta) {