[Bug-mit-scheme] [bug #34425] Uncaught arithmetic exception with line-wraps in OS X edwin

[anonymous]

URL:
  <http://savannah.gnu.org/bugs/?34425>

                 Summary: Uncaught arithmetic exception with line-wraps in OS
X edwin
                 Project: MIT/GNU Scheme
            Submitted by: None
            Submitted on: Wed 28 Sep 2011 10:20:35 PM UTC
                Category: edwin
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect behavior
                  Status: None
                 Privacy: Public
             Assigned to: None
         Originator Name: Ian Jacobi
        Originator Email: address@hidden
             Open/Closed: Open
         Discussion Lock: Any
                Keywords: 

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Details:

I am able to consistently kill mit-scheme in OS X/X11 when using edwin by
doing the following:

On a new line in edwin, create a literal tab character (e.g. in Fundamental
mode) and then insert several characters.  Then, proceed to insert characters
BETWEEN the tab and the last (non-line-feed) character on the line until the
cursor would normally line-wrap (i.e. the highlighted character is the
character before the '\' line-wrap marker).

Typing any additional character such that the cursor would line-wrap causes
the uncaught arithmetic exception (appearing to be a divide-by-zero).

This exception is also raised if the line-feed character at the end of the
line is deleted with a backspace (such that the subsequent line would become
concatenated to the end of the line-wrapped line).

In gdb, this backtrace reports as follows (in the i386 build):

(gdb) bt
#0  0x00ab94ff in ?? ()
#1  0x000007fe in ?? ()
Cannot access memory at address 0x3ffffff

and my registers are as follows:

(gdb) info registers
eax            0x13c0   5056
ecx            0x13c0   5056
edx            0x0      0
ebx            0x4000   16384
esp            0x80d94  0x80d94
ebp            0x3ffffff        0x3ffffff
esi            0x406ebd0        67562448
edi            0xe129b4 14756276
eip            0xab94ff 0xab94ff
eflags         0x10246  66118
cs             0x1b     27
ss             0x23     35
ds             0x23     35
es             0x23     35
fs             0x0      0
gs             0xf      15

Nearby dissassembled instructions include:

0x00ab94e8:     or     $0x1a,%edx
0x00ab94eb:     ror    $0x6,%edx
0x00ab94ee:     cmp    $0x68000000,%edx
0x00ab94f4:     je     0xab9513
0x00ab94f6:     mov    %ebx,%eax
0x00ab94f8:     mov    %ecx,%eax
0x00ab94fa:     mov    %eax,%edx
0x00ab94fc:     sar    $0x1f,%edx
0x00ab94ff:     idivl  0x600(%esi)
0x00ab9505:     shl    $0x6,%eax
0x00ab9508:     or     $0x1a,%eax
0x00ab950b:     ror    $0x6,%eax
0x00ab950e:     mov    %eax,0x8(%esi)
0x00ab9511:     jmp    0xab94b9
0x00ab9513:     mov    %ecx,%eax
0x00ab9515:     mov    %eax,%edx

I am running OS X 10.7 and have observed this bug in the binary build of
MIT-Scheme Release 9.0.1 (Microcode 15.1 || Runtime 15.7 || SF 4.41 ||
LIAR/i386 4.118 || Edwin 3.116) in both the i386 and x86-64 builds (albeit
with different register values), and also observed what I believe was this bug
in OS X 10.6.

In OS X 10.7, I am using Apple's stock X11: XQuartz 2.6.3 (xorg-server 1.10.2)



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File Attachments:


-------------------------------------------------------
Date: Wed 28 Sep 2011 10:20:35 PM UTC  Name: test  Size: 237B   By: None
An example file which works with an 80-character line-wrap.
<http://savannah.gnu.org/bugs/download.php?file_id=24037>

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