[Octave-bug-tracker] [bug #47759] scanf should return min/max value on integer range overflow

[Mike Miller]

URL:
  <http://savannah.gnu.org/bugs/?47759>

                 Summary: scanf should return min/max value on integer range
overflow
                 Project: GNU Octave
            Submitted by: mtmiller
            Submitted on: Thu 21 Apr 2016 08:04:08 PM PDT
                Category: Octave Function
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Matlab Compatibility
                  Status: In Progress
             Assigned to: mtmiller
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: dev
        Operating System: Any

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Details:

According to tests in bug #47741, Matlab returns the minimum or maximum
integer value if the converted value overflows the storage limit of a 32-bit
integer (or 64-bit integer if %ld is used).

Octave currently stops conversion when it encounters a value that is out of
range.

Does Matlab also return an errmsg string when a value overflows? What does
Matlab do for the following:


format long
[x, count, errmsg] = sscanf('9999999999', '%d')
[x, count, errmsg] = sscanf('fffffffff', '%x')


The attached diff fixes the bug so overflow values are returned as the min/max
value possible and conversion continues with the next value, but does not set
errmsg. See also bug #46493 for why we can't currently set errmsg on success,
but we can at least mark it as something to fix later for compatibility.



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File Attachments:


-------------------------------------------------------
Date: Thu 21 Apr 2016 08:04:08 PM PDT  Name: scanf-overflow.diff  Size: 3kB  
By: mtmiller

<http://savannah.gnu.org/bugs/download.php?file_id=36978>

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