[patch #6219] Descriptives Dialog

[Jason H Stover]

Follow-up Comment #4, patch #6219 (project pspp):

Here are some details about the segfault: In the data
editor, I added variables v1 and v2, typed in some random
data on the keyboard (about 10 cases in the two columns),
selected the Descriptives procedure with variable v1, hit 'OK'.
psppire segfaulted, and gdb reported this backtrace:

Program received signal SIGSEGV, Segmentation fault.
0xb7276fe4 in _IO_str_overflow_internal () from /lib/libc.so.6
(gdb) bt
#0  0xb7276fe4 in _IO_str_overflow_internal () from /lib/libc.so.6
#1  0xb7276984 in __overflow () from /lib/libc.so.6
#2  0xb726b442 in vsprintf () from /lib/libc.so.6
#3  0x08145bfd in ds_put_vformat (st=0xb734fff4, format=0x84780a0 "",
args_=0x0) at src/libpspp/str.c:1291
#4  0x080a2f67 in create_syntax_string_source (format=0x84780a0 "") at
src/language/syntax-string-source.c:111
#5  0x08070743 in descriptives_dialog (o=0x8381498, data=0x81f5a20) at
src/ui/gui/descriptives-dialog.c:316
#6  0xb776eb6b in IA__g_cclosure_marshal_VOID__VOID (closure=0x8381e18,
return_value=0x0, n_param_values=1, 
    param_values=0xbfbc9e4c, invocation_hint=0xbfbc9d4c,
marshal_data=0x8070510) at gmarshal.c:77
#7  0xb7761cdc in IA__g_closure_invoke (closure=0x8381e18, return_value=0x0,
n_param_values=1, 
    param_values=0xbfbc9e4c, invocation_hint=0xbfbc9d4c) at gclosure.c:490
#8  0xb7772574 in signal_emit_unlocked_R (node=0x8370000, detail=0,
instance=0x8381498, emission_return=0x0, 
    instance_and_params=0xbfbc9e4c) at gsignal.c:2440
#9  0xb7773a9c in IA__g_signal_emit_valist (instance=0x8381498,
signal_id=243, detail=0, 
    var_args=0xbfbca08c "D235ù·230