Now there we got it! For all the java-fonts, the height is about double
what it should be and about all the extra height is used by "leading".
Renaming fontconfig.properties.src to fontconfig.properties did not seem
to make any difference. I can't see leading beeing mentioned anywhere in
that file so maybe that wasn't so surprising. Now is the question how
could be and what do I do about it?
Also, Thanks for all the help!
****** Default font ******
Family

ialog
FontName

ialog.plain
Name

efault
PSName

ialog.plain
toString:javax.swing.plaf.FontUIResource[family=Dialog,name=Default,style=plain,size=1]
attr:java.awt.font.TextAttribute(family)=Default
attr:java.awt.font.TextAttribute(superscript)=0
attr:java.awt.font.TextAttribute(posture)=0.0
attr:java.awt.font.TextAttribute(transform)=java.a wt.font.TransformAttribute@9cab16
attr:java.awt.font.TextAttribute(size)=1.0
attr:java.awt.font.TextAttribute(weight)=1.0
attr:java.awt.font.TextAttribute(width)=1.0
ascent = 0.92163086
descent = 0.2109375
height = 2.1243896
leading = 0.9918213
StrikethroughOffset = -0.36865234
UnderlineOffset = -0.92419624
ROMAN_BASELINE
****** Arial font ******
Family:Arial
FontName:Arial
Name:Arial
PSName:ArialMT
toString:javax.swing.plaf.FontUIResource[family=Arial,name=Arial,style=plain,size=1]
attr:java.awt.font.TextAttribute(family)=Arial
attr:java.awt.font.TextAttribute(superscript)=0
attr:java.awt.font.TextAttribute(posture)=0.0
attr:java.awt.font.TextAttribute(transform)=java.a wt.font.TransformAttribute@9cab16
attr:java.awt.font.TextAttribute(size)=1.0
attr:java.awt.font.TextAttribute(weight)=1.0
attr:java.awt.font.TextAttribute(width)=1.0
ascent = 0.92163086
descent = 0.19555664
height = 1.1499023
leading = 0.032714844
StrikethroughOffset = -0.36865234
UnderlineOffset = -0.92419624
ROMAN_BASELINE