From 40fbc2140bb274581cb8527dcfa51d8d64bb5edd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20M=C3=BCller?= <robytemueller@gmail.com>
Date: Sun, 18 Aug 2024 22:54:44 +0200
Subject: [PATCH] Use `std::string` for `IInput::GetClipboardText`

Simplify clipboard handling by returning an `std::string` and freeing the string returned by SDL immediately, so the clipboard data does not stay in memory unnecessarily after the clipboard has been used until the clipboard data is requested again.

Fix possible TOCTOU when pasting from the clipboard into a lineinput, due to the clipboard data being requested twice.
---
 src/engine/client/input.cpp   | 12 +++++-------
 src/engine/client/input.h     |  3 +--
 src/engine/input.h            |  3 ++-
 src/game/client/lineinput.cpp |  5 ++---
 src/game/editor/editor.cpp    | 10 +++++-----
 5 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/src/engine/client/input.cpp b/src/engine/client/input.cpp
index 5711a5119..0d8b2a345 100644
--- a/src/engine/client/input.cpp
+++ b/src/engine/client/input.cpp
@@ -68,8 +68,6 @@ CInput::CInput()
 
 	m_MouseFocus = true;
 
-	m_pClipboardText = nullptr;
-
 	m_CompositionCursor = 0;
 	m_CandidateSelectedIndex = -1;
 
@@ -90,7 +88,6 @@ void CInput::Init()
 
 void CInput::Shutdown()
 {
-	SDL_free(m_pClipboardText);
 	CloseJoysticks();
 }
 
@@ -303,11 +300,12 @@ const std::vector<IInput::CTouchFingerState> &CInput::TouchFingerStates() const
 	return m_vTouchFingerStates;
 }
 
-const char *CInput::GetClipboardText()
+std::string CInput::GetClipboardText()
 {
-	SDL_free(m_pClipboardText);
-	m_pClipboardText = SDL_GetClipboardText();
-	return m_pClipboardText;
+	char *pClipboardText = SDL_GetClipboardText();
+	std::string ClipboardText = pClipboardText;
+	SDL_free(pClipboardText);
+	return ClipboardText;
 }
 
 void CInput::SetClipboardText(const char *pText)
diff --git a/src/engine/client/input.h b/src/engine/client/input.h
index 908e133e1..90b170f2e 100644
--- a/src/engine/client/input.h
+++ b/src/engine/client/input.h
@@ -74,7 +74,6 @@ private:
 	float GetJoystickDeadzone();
 
 	bool m_InputGrabbed;
-	char *m_pClipboardText;
 
 	bool m_MouseFocus;
 #if defined(CONF_PLATFORM_ANDROID)
@@ -151,7 +150,7 @@ public:
 
 	const std::vector<CTouchFingerState> &TouchFingerStates() const override;
 
-	const char *GetClipboardText() override;
+	std::string GetClipboardText() override;
 	void SetClipboardText(const char *pText) override;
 
 	void StartTextInput() override;
diff --git a/src/engine/input.h b/src/engine/input.h
index 4bb6e67a7..9aa873358 100644
--- a/src/engine/input.h
+++ b/src/engine/input.h
@@ -10,6 +10,7 @@
 
 #include <cstdint>
 #include <functional>
+#include <string>
 #include <vector>
 
 const int g_MaxKeys = 512;
@@ -138,7 +139,7 @@ public:
 	virtual const std::vector<CTouchFingerState> &TouchFingerStates() const = 0;
 
 	// clipboard
-	virtual const char *GetClipboardText() = 0;
+	virtual std::string GetClipboardText() = 0;
 	virtual void SetClipboardText(const char *pText) = 0;
 
 	// text editing
diff --git a/src/game/client/lineinput.cpp b/src/game/client/lineinput.cpp
index 69d7c2818..9c9564a05 100644
--- a/src/game/client/lineinput.cpp
+++ b/src/game/client/lineinput.cpp
@@ -331,10 +331,9 @@ bool CLineInput::ProcessInput(const IInput::CEvent &Event)
 		}
 		else if(ModPressed && !AltPressed && Event.m_Key == KEY_V)
 		{
-			const char *pClipboardText = Input()->GetClipboardText();
-			if(pClipboardText)
+			std::string ClipboardText = Input()->GetClipboardText();
+			if(!ClipboardText.empty())
 			{
-				std::string ClipboardText = Input()->GetClipboardText();
 				if(m_pfnClipboardLineCallback)
 				{
 					// Split clipboard text into multiple lines. Send all complete lines to callback.
diff --git a/src/game/editor/editor.cpp b/src/game/editor/editor.cpp
index 814749c1b..9eab3909c 100644
--- a/src/game/editor/editor.cpp
+++ b/src/game/editor/editor.cpp
@@ -3665,12 +3665,12 @@ void CEditor::DoColorPickerButton(const void *pId, const CUIRect *pRect, ColorRG
 	{
 		if(ButtonResult == 1)
 		{
-			const char *pClipboard = Input()->GetClipboardText();
-			if(*pClipboard == '#' || *pClipboard == '$') // ignore leading # (web color format) and $ (console color format)
-				++pClipboard;
-			if(str_isallnum_hex(pClipboard))
+			std::string Clipboard = Input()->GetClipboardText();
+			if(Clipboard[0] == '#' || Clipboard[0] == '$') // ignore leading # (web color format) and $ (console color format)
+				Clipboard = Clipboard.substr(1);
+			if(str_isallnum_hex(Clipboard.c_str()))
 			{
-				std::optional<ColorRGBA> ParsedColor = color_parse<ColorRGBA>(pClipboard);
+				std::optional<ColorRGBA> ParsedColor = color_parse<ColorRGBA>(Clipboard.c_str());
 				if(ParsedColor)
 				{
 					m_ColorPickerPopupContext.m_State = EEditState::ONE_GO;