Re: difficulties when building from svn, segfault, backtrace

[Benno Schulenberg]

Hi Gavin,

On Wed, May 7, 2014, at 0:09, Gavin Smith wrote:
> On Tue, May 6, 2014 at 9:04 PM, Benno Schulenberg <address@hidden> wrote:
> > $ info/ginfo doc/info.info
> > Welcome to Info version 5.2. Type h for help, m for menu item.Segmentation 
> > fault
> >
> > Wow.
> >
> > The doc/info.info seems to be fine, though, I can read it okay with the
> > system's own info command.  And starting info/ginfo with other arguments
> > (grep, sed, find) or without any argument works fine too.  So, what's up
> > with this segfault?
> 
> I'll look into it. (Note you should really do "info/ginfo --file
> ./doc/info.info" instead to open a file with that path.)

Indeed, using the option --file it opens and works fine.  Thanks.

But meanwhile I figured out how to add arguments to the program name
given to gdb, and got the following backtrace:

Welcome to Info version 5.2. Type h for help, m for menu item.
Program received signal SIGSEGV, Segmentation fault.
0x001e6bb6 in ?? () from /lib/i386-linux-gnu/libc.so.6
(gdb) bt
#0  0x001e6bb6 in ?? () from /lib/i386-linux-gnu/libc.so.6
#1  0x0804dbb4 in info_add_extension (
    dirname=0x80b0148 "ense\177\065\070\061\060\064\nNode: 
Index\177\070icense\177\065\070\061\060\064\nNode: 
Index\177\070icense\177\065\070\061\060\064\nNode: 
Index\177\070icense\177\065\070\061\060\064\nNode: 
Index\177\070icense\177\065\070\061\060\064\nNode: 
Index\177\070icense\177\065\070\061\060\064\nNode: 
Index\177\070icense\177\065\070\061\060\064\nNode: 
Index\177\070icense\177\065\070\061\060\064\nNode: I"..., 
    filename=0x8098fe8 
"/usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info/
 info.texi.\n\nThis file describes how to use Info describes how tenu-dr"..., 
finfo=0xbffff5c0)
    at filesys.c:241
#2  0x0804da91 in info_file_find_next_in_path (
    filename=0x8098fe8 
"/usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info/
 info.texi.\n\nThis file describes how to use Info describes how tenu-dr"..., 
    path=0x808dbc0 
"/usr/local/share/info:.:/usr/share/info:/usr/local/info:/usr/info:/usr/local/lib/info:/usr/lib/info:/usr/local/gnu/info:/usr/local/gnu/lib/info:/usr/gnu/info:/usr/gnu/lib/info:/opt/gnu/info:/usr/share"...,
 diridx=0xbffff58c, 
    finfo=0xbffff5c0) at filesys.c:197
#3  0x0804dafd in info_file_in_path (
    filename=0x8098fe8 
"/usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info/
 info.texi.\n\nThis file describes how to use Info describes how tenu-dr"..., 
    path=0x808dbc0 
"/usr/local/share/info:.:/usr/share/info:/usr/local/info:/usr/info:/usr/local/lib/info:/usr/lib/info:/usr/local/gnu/info:/usr/local/gnu/lib/info:/usr/gnu/info:/usr/gnu/lib/info:/opt/gnu/info:/usr/share"...,
 finfo=0xbffff5c0)
    at filesys.c:210
#4  0x0804d9a9 in info_find_fullpath (
    partial=0x8098fe8 
"/usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info/
 info.texi.\n\nThis file describes how to use Info describes how tenu-dr"..., 
finfo=0xbffff5c0)
    at filesys.c:155
#5  0x0805aa28 in info_find_file (
    filename=0x8098fe8 
"/usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info/
 info.texi.\n\nThis file describes how to use Info describes how tenu-dr"...) 
at nodes.c:654
#6  0x0805c9e8 in begin_multiple_window_info_session (
    filename=0x8098fe8 
"/usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info//usr/local/lib/emacs/info/
 info.texi.\n\nThis file describes how to use Info describes how tenu-dr"..., 
    nodenames=0x80b0488, error=0x0) at session.c:130
#7  0x08054203 in main (argc=0, argv=0xbffff81c) at info.c:853

That filename looks messed up.


> > $ info/ginfo doc/what.info
> >
> > It does not segfault but the screen is blank and the status line says:
> > Info: (*no file*)*no node*, 0 lines --All

It segfaults, however, as soon as I hit the spacebar (or a cursor key):

Program received signal SIGSEGV, Segmentation fault.
0x0805f76b in forward_move_node_structure (window=0x80aa568, behaviour=0) at 
session.c:2011
2011            if (!window->node->next &&
(gdb) bt
#0  0x0805f76b in forward_move_node_structure (window=0x80aa568, behaviour=0) 
at session.c:2011
#1  0x0805e4f8 in _scroll_forward (window=0x80aa568, count=31, key=32 ' ', 
behaviour=0) at session.c:1191
#2  0x0805e61b in info_scroll_forward (window=0x80aa568, count=1, key=32 ' ') 
at session.c:1238
#3  0x080646bb in info_dispatch_on_key (key=32 ' ', map=0x807eeb0) at 
session.c:5021
#4  0x0805cc93 in info_read_and_dispatch () at session.c:253
#5  0x0805cba2 in info_session () at session.c:203
#6  0x08054208 in main (argc=0, argv=0xbffff81c) at info.c:855


> PS the required version of automake might be 1.14 for a good reason.

Of course.  But I would have expected the build to choke somewhere,
not to get a program with a strange bug compiled into it.

Benno

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