Support nullptr char pointers

[lanyizi]

imgui/imgui_widgets.cpp

Lines 3874 to 3877 in 655aae5

	void ImGuiInputTextCallbackData::InsertChars(int pos, const char* new_text, const char* new_text_end)
	{
	const bool is_resizable = (Flags & ImGuiInputTextFlags_CallbackResize) != 0;
	const int new_text_len = new_text_end ? (int)(new_text_end - new_text) : (int)strlen(new_text);

An empty std::string_view returns nullptr from its data() and 0 from its size().
One might expect that by calling Insert(p, view.data(), view.size()) should work, but when view is empty, this actually leads into dereferencing a null pointer because of strlen(new_text).

Could Dear ImGui support null char* in its API?

[ocornut]

Hello,
Thanks for reporting. This is analogous to #3615 we did for TextUnformatted().
I have pushed a fix 6417268.
Proposed fix #6566 would erroneously silently not-crash on (NULL,non-NULL) combo so I am opting for a == test there.
Thank you!