Patch from Matthias Clasen (#59806)

Patch from Matthias Clasen (#59806)

Wed Sep 19 14:17:31 2001  Owen Taylor  <otaylor@redhat.com>

	Patch from Matthias Clasen (#59806)

	* configure.in: Check for vasprintf().

	* glib/gmem.[ch]: Add g_mem_vtable_is_set() to be used
	for efficiency hacks to avoid extra copies when not
	needed.

	* glib/gstrfuncs.c: Use vasprintf() to implement
	g_strdup_printf() when available.

	* glib/gmessages.c (g_logv): Avoid using
	printf_string_upper_bound() when we have have vsnprintf.

	* glib/gmessages.c (printf_string_upper_bound): Don't
	segfault when warning about positional parameters.