mORMot Open Source

Hi,

after having used SynPDF for years without any issues, I stumbled upon a small problem today which leads to corrupted PDFs. I found out what's happening, but not sure about the proper solution.

So basically, my application tried to create a pdf that contains a Bitmap with a height of 1 pixel. In the procedure TPdfEnum.DrawBitmap, the bitmap size R is rescaled to variable Box in the function BoxI/RectI. But this rescaling results in a height of 0, which then leads to a corrupted PDF file (often, the PDF ends up corrupt, and if not, it usually does not continue drawing any elements that were added after the bitmap).

1. Why are both the right and bottom coordinates for variable Box shifted by -1 in function RectI?
2. Maybe there should be some error handling when height or width of the variable Box is 0, or the bitmap should not be drawn at all?

See the code section below. variable ClipRc is checked if it's actually a valid rectangle, but variable Box is not.

    // draw the bitmap on the PDF canvas
    with Canvas do begin
      R := Rect(xd, yd, wd+xd, hd+yd);
      NormalizeRect(R);
      Box := BoxI(R,true);
      ClipRc := GetClipRect;
      if (ClipRc.Width>0) and (ClipRc.Height>0) then
        Doc.CreateOrGetImage(B, @Box, @ClipRc) else // use cliping
        Doc.CreateOrGetImage(B, @Box, nil);
      // Doc.CreateOrGetImage() will reuse any matching TPdfImage
      // don't send bmi and bits parameters here, because of StretchDIBits above
    end;