[Bug-apl] another dfun bug

[Xiao-Yong Jin]

Hello, perhaps it’s another dfun bug.

      )clear
CLEAR WS
      ∇z←x f y
[1] x{⍺ g ⍵}y 
[2] →0
[3] ∇
items_allocated = 16
items[7] = 'yUSER-F2 λ1'xENDLVALUE3«0»→ENDL
idx = 7

==============================================================================
Assertion failed: 0 && "Bad index"
in Function:      operator[]
in file:          Simple_string.hh:150

Call stack:

----------------------------------------
-- Stack trace at Simple_string.hh:150
----------------------------------------
========================================

SI stack:


==============================================================================
*** immediate_execution() caught other exception ***