Crash when defining function named with a number

[Matthew Mundell]

Evaluating (defun 2 () t) causes the crash traced below.  Perhaps
Fdefun should check that NAME is a symbol, as in the following patch.

===================================================================
RCS file: /cvsroot/emacs/emacs/src/eval.c,v
retrieving revision 1.217
diff -u -r1.217 eval.c
--- src/eval.c  1 Jun 2004 23:21:55 -0000       1.217
+++ src/eval.c  11 Jun 2004 21:18:27 -0000
@@ -617,6 +617,7 @@
   register Lisp_Object defn;

   fn_name = Fcar (args);
+  CHECK_SYMBOL (fn_name);
   defn = Fcons (Qlambda, Fcdr (args));
   if (!NILP (Vpurify_flag))
     defn = Fpurecopy (defn);


(gdb) r -Q
The program being debugged has been started already.
Start it from the beginning? (y or n) y
Starting program: /home/matt/src/emacs-clean.bak_exclude/src/emacs -Q

Program received signal SIGSEGV, Segmentation fault.
0x08187404 in Fdefun (args=140083573) at eval.c:623
623       if (CONSP (XSYMBOL (fn_name)->function)
(gdb) xbacktrace
"defun"
"eval"
"eval-last-sexp-1"
"eval-last-sexp"
"call-interactively"
(gdb) bt
#0  0x08187404 in Fdefun (args=140083573) at eval.c:623
#1  0x08189a3a in Feval (form=138229580) at eval.c:2025
#2  0x0818a3ef in Ffuncall (nargs=2, args=0xbfffef04) at eval.c:2726
#3  0x081b723e in Fbyte_code (bytestr=140685825, vector=1, 
maxdepth=-1073746176) at bytecode.c:689
#4  0x0818a7dc in funcall_lambda (fun=137101844, nargs=1, 
arg_vector=0xbffff044) at eval.c:2913
#5  0x0818a2cd in Ffuncall (nargs=2, args=0xbffff040) at eval.c:2783
#6  0x081b723e in Fbyte_code (bytestr=140685801, vector=1, 
maxdepth=-1073745856) at bytecode.c:689
#7  0x0818a7dc in funcall_lambda (fun=137102628, nargs=1, 
arg_vector=0xbffff1b4) at eval.c:2913
#8  0x0818a2cd in Ffuncall (nargs=2, args=0xbffff1b0) at eval.c:2783
#9  0x08185c14 in Fcall_interactively (function=138878177, 
record_flag=17313794, keys=138567212)
    at callint.c:862
#10 0x0813122c in Fcommand_execute (cmd=138878177, record_flag=138510353, 
keys=16, special=16)
    at keyboard.c:9682
#11 0x08125aee in command_loop_1 () at keyboard.c:1740
#12 0x081885ee in internal_condition_case (bfun=0x8125730 <command_loop_1>, 
handlers=138571281,
    hfun=0x8125210 <cmd_error>) at eval.c:1333
#13 0x0812556e in command_loop_2 () at keyboard.c:1271
#14 0x0818812b in internal_catch (tag=16, func=0x8125540 <command_loop_2>, 
arg=138510353) at eval.c:1094
#15 0x0812550e in command_loop () at keyboard.c:1250
#16 0x08124f94 in recursive_edit_1 () at keyboard.c:961
#17 0x081250d1 in Frecursive_edit () at keyboard.c:1022
#18 0x081237d0 in main (argc=2, argv=0xbffffa54) at emacs.c:1693