Regression: Leaf node width doesn't adjust after renaming

[Thomas1664]

After setting the names of the leaf nodes to a longer name than they used to be, the backgouund color doesn't cover the full name any longer.

This works fine in version 3.1.3 but doesn't work at commits 55865ebe29adb3156983fdbb8c66595931c010e8 and 0f661dbf4dd2bf5da32659a8ca5ecb619004af6f.