Segfault for iteration specs like ":1000" and "1000"

[Christian Speckner]

The syntax rules of SINDARIN allow for iteration specs which omit the iteration count (in which case, I presume, WHIZARD should insert the default). However, doing so makes WHIZARD segfault, the relevant part of the backtrace being

#0  parse_node_get_sub_ptr (node=Cannot access memory at address 0x0
) at parser.f90:514
#1  0xb7c232c7 in eval_node_compile_expr (en=0x0, pn=Cannot access memory at address 0x0
) at expressions.f90:2164
#2  0xb7c04446 in eval_tree_init_expr (eval_tree=..., parse_node=Cannot access memory at address 0x0
) at expressions.f90:5925
#3  0xb7c030d6 in eval_int (parse_node=Cannot access memory at address 0x0
) at expressions.f90:6265
#4  0xb7df9ccf in cmd_iterations_execute (iterations=..., global=...) at commands.f90:4774
#5  0xb7e3925e in command_execute (command=..., global=...) at commands.f90:928
#6  0xb7df2b9e in command_list_execute (cmd_list=..., global=...) at commands.f90:5544
#7  0xb7e3bf5f in whizard_process_stream (stream=..., lexer=..., quit=.FALSE., quit_code=0) at whizard.f90:278
#8  0xb7e3c5c0 in whizard_process_file (file=..., quit=.FALSE., quit_code=0) at whizard.f90:256
#9  0xb7f71b37 in MAIN__ () at main.f90:301

The simplest solution I guess would be just disabling this feature (the point of which I am not seeing anyway).

[Christian Speckner]

The same happens for iterations = 1000.

[kilian]

Making the numbers optional was inherited from W1 where one could write a 0 to indicate the default. I agree that this feature is not really needed. In particular, in W2 one can insert an arithmetic expression, which adds sufficient flexibility.

In the revised syntax r2797, the form x:y is enforced with both x and y mandatory.