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+SYNOPSIS
+	void dangling_lfun_closure()
+
+DESCRIPTION
+	Handle a dangling lfun-closure.
+
+	This is called when the gamedriver executes a closure using a
+	vanished lfun. A proper handling is to raise a runtime error.
+
+	Technical:
+	  Upon replacing programs (see efun replace_program()), any
+	  existing lambda closures of the object are adjusted to the
+	  new environment. If a closure uses a lfun which vanished in
+	  the replacement process, the reference to this lfun is
+	  replaced by a reference to this function. The error will
+	  then occur when the execution of the adjusted lambda reaches
+	  the point of the lfun reference. There are two reasons for
+	  the delayed handling. First is that the program replacement
+	  and with it the closure adjustment happens at the end of a
+	  backend cycle, outside of any execution thread: noone would
+	  see the error at this time.  Second, smart closures might
+	  know/recognize the program replacement  and skip the call to
+	  the vanished lfun.
+
+SEE ALSO
+	closures(LPC)