AG_XFUNC Corruption Avoidance

The string containing the argument list was previously used in place, but since the area is within the terminal system output buffer, it was subject to possible corruption by other functions that use the output system. This could have interfered with the operation of XGETARG(S). For example, in the following SBX code, the second XGETARG might have returned incorrect information due to potential sharing of the same buffer space with DEBUG.PRINT:

XGETARG 1,ARG1

DEBUG.PRINT "ARG1 = "+ARG1

XGETARG 2,ARG2

 

This patch eliminates the danger of such a conflict.