libstdc++/7206: gcc 3.1:rewind(fptr) doesn`t work after fwscanf (fptr,L"%c%c",...) on opened with "w+" file.

libstdc++/7206: gcc 3.1:rewind(fptr) doesn`t work after fwscanf (fptr,L"%c%c",...) on opened with "w+" file.

[johnb]

>Number:         7206
>Category:       libstdc++
>Synopsis:       gcc 3.1:rewind(fptr) doesn`t work after fwscanf (fptr,L"%c%c",...) on opened with "w+" file.
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jul 04 05:26:03 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     johnb@stl.sarov.ru
>Release:        gcc 3.1
>Organization:
>Environment:
Red Hat Linux release 7.2 (Enigma), glibc 2.2.4
>Description:
The rewind() function doesn`t work after first call to fwscanf(), second call to fwscanf() continue reading the stream from last unread position, not the first one as should be after call to rewind(). This situation doesn`t exist with fscanf(). See the testcases.
>How-To-Repeat:
Just compile with gcc 3.1, for example:
$gcc31 wrewind.c -o wrewind
$wrewind

You`ll get "...failed" message.
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted:
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Re: libstdc++/7206: gcc 3.1:rewind(fptr) doesn`t work after fwscanf (fptr,L"%c%c",...) on opened with "w+" file.

[paolo]

Synopsis: gcc 3.1:rewind(fptr) doesn`t work after fwscanf (fptr,L"%c%c",...) on opened with "w+" file.

Responsible-Changed-From-To: unassigned->paolo
Responsible-Changed-By: paolo
Responsible-Changed-When: Fri Jul  5 05:10:08 2002
Responsible-Changed-Why:
    .
State-Changed-From-To: open->closed
State-Changed-By: paolo
State-Changed-When: Fri Jul  5 05:10:08 2002
State-Changed-Why:
    rewind.c (and also wrewind.c, which is missing, by the way)
    is a pure "C" testcase, therefore libstdc++ (as you
    categorized the PR) *cannot* be involved. The problem you
    are reporting, *if* real, would concern the behaviour of
    some "C" library (glibc2.2.4 that is) functions, not gcc
    and this is not the right place to submit it.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=7206