[dev] [PDFFILTER] different rRect value for "A4" and "Letter"

[马珍杰]

Hi

I was debuging the pdffilter in OOO310_m19, I created two documents by
clicking File>>New>>TextDocument. One document was named "Letter.odt" and
with Page format "Letter".the other document was named "A4.odt" and with
Page format "A4". Both documents were set with Margins Left:0.00",
Right:0.00", Top:0.00", Bottom:0.00".

I set a breakpoint in the following function.
void PDFWriter::DrawRect( const Rectangle& rRect )
{
    ((PDFWriterImpl*)pImplementation)->drawRectangle( rRect );
}

Then there was something intersting in parameter rRect, rRect had differenct
values in these two documents,
"Letter.odt":   rRect{nLeft=3135 nTop=568 nRight=15373 nbottom=16406}
"A4.odt":        rRect{nLeft=3303 nTop=568 nRight=15207 nbottom=17404}

I thought "nLeft" and "nTop" should have the same value for both documents,
but actually they didn't .

The most weird is I created two documents on a diffenent machine with the
same document title, same page format and same mragins, and got a different
value:
"Letter.odt":   rRect{nLeft=1348 nTop=568 nRight=13586 nbottom=16406}
"A4.odt":        rRect{nLeft=1514 nTop=568 nRight=13422 nbottom=17400}

Does anyone explain why ?

Thanks
James Ma