[ox/std] Fix string append issues

deps/ox/src/ox/std/string.hpp

@@ -392,7 +392,7 @@ template<std::size_t SmallStringSize_v>
 constexpr BasicString<SmallStringSize_v> BasicString<SmallStringSize_v>::operator+(const char *str) const noexcept {
 	const std::size_t strLen = ox::strlen(str);
 	const auto currentLen = len();
-	BasicString<SmallStringSize_v> cpy(currentLen + strLen);
+	BasicString<SmallStringSize_v> cpy;
 	cpy.m_buff.resize(m_buff.size() + strLen);
 	ox::listcpy(&cpy.m_buff[0], m_buff.data(), currentLen);
 	ox::listcpy(&cpy.m_buff[currentLen], str, strLen);
@@ -423,7 +423,7 @@ constexpr BasicString<SmallStringSize_v> BasicString<SmallStringSize_v>::operato
 	const std::size_t strLen = src.len();
 	const auto currentLen = len();
 	BasicString<SmallStringSize_v> cpy(currentLen + strLen);
-	cpy.m_buff.resize(m_buff.size() + strLen + 1);
+	cpy.m_buff.resize(m_buff.size() + strLen);
 	ox::listcpy(&cpy.m_buff[0], m_buff.data(), currentLen);
 	ox::listcpy(&cpy.m_buff[currentLen], src.data(), strLen);
 	cpy.m_buff[cpy.m_buff.size() - 1] = 0;

src/nostalgia/modules/core/src/studio/tilesheeteditor/tilesheeteditor-imgui.cpp

@@ -445,7 +445,7 @@ void TileSheetEditorImGui::drawPaletteMenu() noexcept {
 	}
 	if (ig::DragDropTarget const dragDropTarget; dragDropTarget) {
 		auto const [ref, err] = ig::getDragDropPayload<studio::FileRef>("FileRef");
-		if (!err) {
+		if (!err && endsWith(ref.path, FileExt_npal)) {
 			auto const oldVal = m_selectedPaletteIdx;
 			std::ignore = ox::findIdx(files.begin(), files.end(), ref.path).moveTo(m_selectedPaletteIdx);
 			if (oldVal != m_selectedPaletteIdx) {