libstdc++/10478: stdio_filebuf corrupts output for buffer sizes 1,2,3The

[Hans.Ranke@ei.tum.de]

>Number:         10478
>Category:       libstdc++
>Synopsis:       stdio_filebuf corrupts output for buffer sizes 1,2,3The
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Apr 24 10:06:01 UTC 2003
>Closed-Date:
>Last-Modified:
>Originator:     Hans Ranke <Hans.Ranke@ei.tum.de>
>Release:        3.2.2
>Organization:
>Environment:
Red Hat Linux 8.0
>Description:
The __gnu_cxx::stdio_filebuf has an optional argument for the
desired buffer size. However, if __size is set to 1, 2, or 3,
only every (__size+1)th character will be written out.
>How-To-Repeat:
See attached file.
The program is supposed to output a constant string, followed by the buffer size, for the buffer sizes 0 .. 5 to the file "testout".
I get the following output:

abcdefghijklmnopqrstuvwxyz 0
bdfhjlnprtvxz 1
cfilorux 2
dhlptx 3
abcdefghijklmnopqrstuvwxyz 4
abcdefghijklmnopqrstuvwxyz 5

For the sizes 0, 4 and 5, the output is as expected, for 1, 2 and 3, only every 2nd, 3rd or 4th character is written.
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted:
----gnatsweb-attachment----
Content-Type: application/octet-stream; name="test1.cc"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="test1.cc"

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