Comment 1 for bug 1011977

I would say that the size is totalled, maybe you have checked some really small addons: try with Firefox: if you select any of the unchecked addons, (assuming that you already have FF installed) the total size will show x MB to download, and the size to download grows with each selected addon (as these are quite big). However when selecting addons it hides the "on disk size", and only displays "to download" and "when installed" size.
But for example with Geany (I don't have it installed), when I select the geany-plugins addon, the total size grows, as expected. Regardless of all this, I am setting this to confirmed and Low, as the installation state bar is still above the total size, and the total size is still between the package-specific information for the app.

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