The current version of CSS is CSS2.1. With the change from CSS1 to CSS2 the mapping of px to pt was changed to '1 px=0.75 pt'. So CSS now uses '96 px=1 in'. Currently LO uses '90 px=1 in'. That should be changed to keep up with the current CSS version.
For reference see the list in the paragraph starting "Absolute length units.." in the linked page.
Xisco Fauli committed a patch related to this issue.
It has been pushed to "master":
tdf#97275 SVGIO: Change default PPI to 96 in svg import...
It will be available in 5.2.0.
The patch should be included in the daily builds available at
http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
Affected users are encouraged to test the fix and report feedback.
Is this related to the wrong values in bug 99088?
And first of all: Is the issue solved? -> NEEDINFO
I think, that it is not related to bug 99088, because this issue is about converting units, when inserting (read) a svg-graphic.