In maven output same sizes are logged, still css is compressed

[maltindal]

I realized in the maven output that in case input and output files are defined to be the same file, the logged values are same like
styles.css (1234b) -> styles.css (1234b)[100%]

I guess it is because the same length is called on the file reference pointing to the same file, but I'm not sure. Still the css file was processed when I checked in the output folder.
Basically compression works fine, but the output when running maven I found confusing.

I used the plugin with version 1.5.1.
warSourceDirectory and webappDirectory are set to the same value.