I'm not sure if this is Qt related, but it affects nearly all the KDE applications I tried while not affecting apps like LibreOffice, GIMP, etc.  Please change product/component as needed.

Observed on this 13.04 (Raring) machine as well as on another machine running 12.04.

The test subject in this bug report is the character "0" (zero) of the font FreeSerif with the Regular style when displayed at sizes above 48pt.

I will attach a screenshot showing the following:
1) The file /usr/share/fonts/truetype/freefont/FreeSerif.ttf opened in a large size in kfontview version 1.1.  The zero displays just fine.
2) Kate opened with some sample text set to FreeSerif regular, size 48.1.  The zero is malformed.
3) A font selection window showing the mishapped zero at size 48.1.

Other tests:

LibreOffice, the GIMP, and Inkscape are not affected: the zero displays just fine at any size.

Calligra programs (Words, Sheets) display the malformed zero at a similar actual display size.  The zoom being used makes a difference, so the zero is fine at size 200 when viewed at a zoom of 20%, but it is malformed at size 20 when viewed at a zoom of 500%.

Karbon's multi-line text tool shows the zero wrong based on zoom size (like the Calligra programs).  However its ArtisticText tool will malform the zero at any size or zoom.

 

Reproducible: Always




MD5 of font file (13.04 version):
660f09351765961f9ca62a713b5fbfc4  FreeSerif.ttf