On Friday 18 January 2002 4:29 pm, Jean-Marc Lasgouttes wrote:
> >>>>> "Angus" == Angus Leeming <[EMAIL PROTECTED]> writes:
>
> Angus> On Friday 18 January 2002 4:04 pm, Jean-Marc Lasgouttes wrote:
> Angus> Where do you want me to add the std::flush?
> >> Because I know it exists and because it may magically repair some
> >> broken insternal thing. I don't know really.
>
> Angus> That was "where" not "why". But I'll try.
>
> Right. I don't know actually.
Got it! The bug lies in the position counters of ostringstream.
basic_stringbuf actually. Sometimes they ain't being set correctly.
Importantly, they are used by the basic_stringbuf::str() function.
The code does some comparisons of position variables to ascertain what to
print out. We can force things to behave as we expect by making an explicit
ostringstream::seekp(std::ios::beg) call before calling ostringstream::str().
For reference, here's the code in basic_stringbuf::str(). Complex!
I've attached a patch that cures the problem reliablely.
Angus
/*
* basic_string str() const
*/
template<class charT, class traits, class Allocator>
basic_string<charT, traits, Allocator>
basic_stringbuf<charT, traits, Allocator>::str() const
{
if ( end_pos == 0 ) return string_type();
if ( (end_pos > ( pptr() - pbase() )) && (end_pos > ( egptr() - eback() )) )
return string_type(data_, end_pos);
else
{
if ( ( pptr() - pbase() ) > ( egptr() - eback() ) )
return string_type(data_, pptr() - pbase() );
else
return string_type(data_, egptr() - eback() );
}
}
Index: src/LaTeXFeatures.C
===================================================================
RCS file: /usr/local/lyx/cvsroot/lyx-devel/src/LaTeXFeatures.C,v
retrieving revision 1.53
diff -u -p -r1.53 LaTeXFeatures.C
--- src/LaTeXFeatures.C 2002/01/10 10:05:43 1.53
+++ src/LaTeXFeatures.C 2002/01/18 17:57:13
@@ -339,14 +339,18 @@ string const LaTeXFeatures::getTClassPre
// the text class specific preamble
LyXTextClass const & tclass = textclasslist.TextClass(params.textclass);
ostringstream tcpreamble;
-
+
tcpreamble << tclass.preamble();
for (layout_type i = 0; i < tclass.numLayouts(); ++i) {
if (layout[i]) {
- tcpreamble << tclass[i].preamble();
+ tcpreamble << tclass[i].preamble();
}
}
+
+ // DEC's implementation of ostringstream has a bug which can be
+ // overcome with this forcing.
+ tcpreamble.seekp(std::ios::beg);
return tcpreamble.str().c_str();
}
