crash on powerpc-ibm-aix5.1.0.0

[Dan Nicolaescu]

Emacs currently crashes when trying to build on powerpc-ibm-aix5.1.0.0
I have a successful installation from May 15th on the same machine. 

This patch is needed to be able to build on that machine:

--- emacs/src/m/ibmrs6000.h~        2004-09-06 11:47:48.000000000 -0700
+++ emacs/src/m/ibmrs6000.h 2005-04-17 19:05:46.000000000 -0700
@@ -112,7 +112,7 @@
 #define OBJECTS_MACHINE hftctl.o
 #endif
 
-#ifndef USG5_4
+#ifndef USG5
 #define C_SWITCH_MACHINE -D_BSD
 #endif
 
The crash is when trying to run temacs -l loadup:

(gdb) r -l loadup
The program being debugged has been started already.
Start it from the beginning? (y or n) y

Starting program: /ptmp/dann/objs/src/temacs -l loadup

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1]
0x10242be8 in _free_internal (ptr=0x20508000) at 
/ptmp/dann/emacs/src/gmalloc.c:1026
1026              i = _heapinfo[i].free.prev;
(gdb) bt
#0  0x10242be8 in _free_internal (ptr=0x20508000)
    at /ptmp/dann/emacs/src/gmalloc.c:1026
#1  0x10243948 in free (ptr=0x20508000) at /ptmp/dann/emacs/src/gmalloc.c:1235
#2  0x1024370c in _free_internal (ptr=0x20508000)
    at /ptmp/dann/emacs/src/gmalloc.c:1188
#3  0x10243948 in free (ptr=0x20508000) at /ptmp/dann/emacs/src/gmalloc.c:1235
#4  0x1002af10 in emacs_blocked_free (ptr=0x20508000)
    at /ptmp/dann/emacs/src/alloc.c:1202
#5  0x10243938 in free (ptr=0x20508000) at /ptmp/dann/emacs/src/gmalloc.c:1233
#6  0x1002a4ec in xfree (block=0x20508000) at /ptmp/dann/emacs/src/alloc.c:791
#7  0x10004c44 in pop_frame_kboard () at /ptmp/dann/emacs/src/keyboard.c:1153
#8  0x100f7748 in display_mode_line (w=0x20451600, face_id=MODE_LINE_FACE_ID, 
    format=541346947) at /ptmp/dann/emacs/src/xdisp.c:15891
#9  0x100f74dc in display_mode_lines (w=0x20451600)
    at /ptmp/dann/emacs/src/xdisp.c:15839
#10 0x100f7230 in redisplay_mode_lines (window=541398532, force=0)
    at /ptmp/dann/emacs/src/xdisp.c:15797
#11 0x100e1480 in echo_area_display (update_frame_p=1)
    at /ptmp/dann/emacs/src/xdisp.c:8248
#12 0x100de334 in message3_nolog (m=541640579, nbytes=29, multibyte=0)
    at /ptmp/dann/emacs/src/xdisp.c:7140
#13 0x100ddfcc in message3 (m=541640579, nbytes=29, multibyte=0)
    at /ptmp/dann/emacs/src/xdisp.c:7075
#14 0x100de7ac in message_with_string (m=0x102b9f28 "Loading %s (source)...", 
    string=541640467, log=1) at /ptmp/dann/emacs/src/xdisp.c:7226
#15 0x10034cd0 in Fload (file=541640467, noerror=541343745, 
nomessage=541343745, 
    nosuffix=541343745, must_suffix=541343745) at 
/ptmp/dann/emacs/src/lread.c:898
#16 0x1004c914 in Feval (form=541372781) at /ptmp/dann/emacs/src/eval.c:2218
#17 0x10005264 in top_level_2 () at /ptmp/dann/emacs/src/keyboard.c:1328
#18 0x1004a61c in internal_condition_case (address@hidden: 0x10005244 
<top_level_2>, 
    handlers=541428337, address@hidden: 0x10004c80 <cmd_error>)
    at /ptmp/dann/emacs/src/eval.c:1452
#19 0x100052e4 in top_level_1 () at /ptmp/dann/emacs/src/keyboard.c:1336
#20 0x10049c88 in internal_catch (tag=541417433, 
    address@hidden: 0x100052a4 <top_level_1>, arg=541343745)
    at /ptmp/dann/emacs/src/eval.c:1211
#21 0x10005124 in command_loop () at /ptmp/dann/emacs/src/keyboard.c:1293
#22 0x1000465c in recursive_edit_1 () at /ptmp/dann/emacs/src/keyboard.c:991
#23 0x100048f8 in Frecursive_edit () at /ptmp/dann/emacs/src/keyboard.c:1052
#24 0x100024c0 in main (argc=3, argv=0x2ff21fb4)
    at /ptmp/dann/emacs/src/emacs.c:1780

The backtrace was obtained when using gcc -g -O0

Does anyone have any idea what is wrong? 
I guess I could do a binary search to find out when the problem
started to happen, but that might take a while.

Thanks
                --dan