Pasting non-text input crashes Minetest

[xenonca]

Minetest version

Minetest 5.8.0

Active renderer

OpenGL 4.6

Irrlicht device

No response

Operating system and version

Windows 11

CPU model

No response

GPU model

No response

OpenGL version

4.6

Summary

When trying to paste something that is not text (e.g. a file) into a formspec using Crtl + C and Ctrl + V Minetest will crash with no errors in the logs.

Steps to reproduce

Copy any file with Ctrl + C. Try to paste it into a formspec, e.g. a sign input field, with Ctrl + V.

[Desour]

Can't reproduce on linux with SDL2 irrlicht device.

[rewired-X]

I achieved a similar result, although I am not certain if I can reproduce it the exact same way I did it.
I tried to copy-paste coords from Discord to in-game, and crashed 3 times.
The fourth time I tried, I copied the coords again and pasted, this time it worked.

[fluxionary]

@rewired-X can you post the details of your OS and build? (minetest --version)

[srifqi]

I can confirm this issue on Windows 10 (10.0.19045). This issue does not occur in 5.7.0 or older.

[srifqi]

This issue is caused by minetest/irrlicht#249 (specifically minetest/irrlicht@c766c3a).

Stack trace:

/* 7 */ irr::core::wStringToUTF8(class irr::core::string<char> &,wchar_t const *)
/* 6 */ irr::COSOperator::getTextFromClipboard(void)
/* 5 */ irr::gui::CGUIEditBox::processKey(struct irr::SEvent const &)
/* 4 */ irr::gui::CGUIEditBox::OnEvent(struct irr::SEvent const &)
/* 3 */ irr::gui::CGUIEnvironment::postEventFromUser(struct irr::SEvent const &)
/* 2 */ irr::CIrrDeviceStub::postEventFromUser(struct irr::SEvent const &)
/* 1 */ WndProc(struct HWND__ *,unsigned int,unsigned __int64,__int64)

Possible fix:

diff --git a/source/Irrlicht/COSOperator.cpp b/source/Irrlicht/COSOperator.cpp
index d2b3b8d..33b07ec 100644
--- a/source/Irrlicht/COSOperator.cpp
+++ b/source/Irrlicht/COSOperator.cpp
@@ -162,6 +162,9 @@ const c8* COSOperator::getTextFromClipboard() const
 	wchar_t * buffer = 0;
 
 	HANDLE hData = GetClipboardData( CF_UNICODETEXT );
+	if (hData == NULL) // Probably not in Unicode text format
+		return 0;
+
 	buffer = (wchar_t*) GlobalLock( hData );
 
 	core::wStringToUTF8(ClipboardBuf, buffer);

Documentation for GetClipboardData()

[grorp]

So this doesn't happen with USE_SDL2=TRUE / CIrrDeviceSDL, right? (will become the default on Windows with 5.9.0)

(Also, I'm wondering why the missing null check didn't cause problems before minetest/irrlicht@c766c3a.)

[srifqi]

So this doesn't happen with USE_SDL2=TRUE / CIrrDeviceSDL, right?

Yes, this issue does not occur using SDL2.

(Also, I'm wondering why the missing null check didn't cause problems before minetest/irrlicht@c766c3a.)

My guess is that the old code checks for null-ness of source parameter.

static inline size_t wStringToMultibyte(string<c8>& destination, const wchar_t* source)
{
	const u32 s = source ? (u32)wcslen(source) : 0;
	return wStringToMultibyte(destination, source, s);
}

static size_t wStringToMultibyte(string<c8>& destination, const wchar_t* source, u32 sourceSize)
{
	if ( sourceSize )
	{
		// ...
	}
	else
	{
		destination.clear();
		return 0;
	}
}

[rewired-X]

@fluxionary live from the windows command prompt :P

[grorp]

Possible fix: [...]

Alright, do you want to open a PR?

[srifqi]

do you want to open a PR?

I am planning to do it.