mccolorer crashes when choosing old syntax highlighting menu

Crash happens when using the old syntax highlighting
code and choosing the syntax highlighting menu.

How to reproduce:
Edit a file
Choose options->general menu
Disable colorer
Choose options->syntax highlighting
boom

back trace (without Pavel Tsekov's patch, which only
influences some line offsets)

#0 0x080aaf1e in colorer_get_handle (edit=0x0) at
syntax-colorer-wrapper.c:50
#1 0x080a97ab in colorer_free_syntax_rules (edit=0x0)
at syntax-colorer.cpp:493
#2 0x080a7839 in edit_load_syntax (edit=0x0,
pnames=0xbf94abb8, type=0x0)
at syntax.c:1197
#3 0x080a8ca5 in edit_syntax_dialog () at
choosesyntax.c:66
#4 0x0807952c in menubar_execute (menubar=Variable
"menubar" is not available.
) at menu.c:242
#5 0x08079d98 in menubar_callback (w=0x9a4ff40,
msg=WIDGET_HOTKEY, parm=10)
at menu.c:326
#6 0x08063ebe in dlg_process_event (h=0x9a5ad80,
key=10, event=0xbf94ac64)
at dialog.c:603
#7 0x080640d4 in run_dlg (h=0x9a5ad80) at dialog.c:785
#8 0x080a25f5 in edit_file (_file=0x9a5a380 "boxes.c",
line=0)
at editwidget.c:217
#9 0x0805e39a in do_edit_at_line (what=0x9a5a380
"boxes.c", start_line=0)
at cmd.c:270
#10 0x0805e3e6 in do_edit (what=Variable "what" is not
available.
) at cmd.c:289
#11 0x08095643 in buttonbar_call (bb=Variable "bb" is
not available.
) at widget.c:2279
#12 0x08095831 in buttonbar_callback (w=0x9a59d50,
msg=WIDGET_HOTKEY,
parm=1004) at widget.c:2301
#13 0x08063d17 in dlg_process_event (h=0x9a44298,
key=1004, event=0xbf94ad84)
at dialog.c:614
#14 0x080640d4 in run_dlg (h=0x9a44298) at dialog.c:785
#15 0x08078c16 in main (argc=1, argv=0xbf94bfa4) at
main.c:1675