Reported by user: " I selected blank image, a4 portait, did a little sketch and when i went to resize noticed it was 10000 dpi and the physical print size was 0.2822 x 0.4115 "
Similar issue on another machine when trying to resize, the settings were:
pixels: 1200 x 1750
print-size: 0.2822 x 0.4115 cm
resolution: 4251.9759 px/cm
I can confirm this bug in master.
Made a new custom image with different dpi. In resize image I get
set dpi : dpi reported in dialog
dpi 300: 10000.0000
dpi 131: 9432.0000
dpi 72 : 5184.0000 in
dpi 10: 720.0000
dpi 1 : 72.0000
dpi 0: 0.0001
Bug #333420 seems related - user reported an issue with dragging to increasing brush size.
Fixed in d8b4718394ee25b21330f772ee9568ded070e388
Internal resolution is pixels per point, not ppi/dpi