Frame size calculations incorrect

Is there an existing issue for this?

• I checked and did not find my issue in the already reported ones

Describe the bug

After applying the framing module the exported image size is not as expected.
On hoover tooltip - border size displays: size of the border in percent of the chosen basis.

My setup - simple file with size of 1000x500 pixels.
framing module on, basis auto (same results with width and longer), aspect constant border.
Export - scale set to 1.
Applying different frame thicknesses in %, I get following image sizes while I expected different ones:

0% -1000x500 - 1000x500 - test case
1% -1010x510 - 1020x520 (expected frame thickness of 10 pixels per side)
2% -1020x520 - 1040x540 (expected frame thickness of 20 pixels per side)
3% -1031x531 - 1060x560 (expected frame thickness of 30 pixels per side)
4% -1042x542 - 1080x580 (expected frame thickness of 40 pixels per side)
5% -1053x553 - 1100x600 (expected frame thickness of 50 pixels per side)
10% -1111x611 - 1200x700 (expected frame thickness of 100 pixels per side)
20% -1250x750 - 1400x900 (expected frame thickness of 200 pixels per side)
30% -1429x929 - 1600x1100 (expected frame thickness of 300 pixels per side)
40% -1667x1167 - 1800x1300 (expected frame thickness of 400 pixels per side)
50% -2000x1500 - 2000x1500 (as expected - frame thickness of 500 pixels per side)

1. tooltip description - is the thickness of border per side or total thickness per direction ?

Steps to reproduce

use simple file with known dimensions.
Setup export with scale 1
setup framing module with basis set to auto and constant border for aspect
adjust frame thickness to specific values and export image.
compare with expected values.

Expected behavior

Tooltip suggests the calculation based on the input picture while the resulting frames are calculated as a percentage of output picture. Suggestion to change tooltip description ?

Logfile | Screenshot | Screencast

No response

Commit

No response

Where did you obtain darktable from?

darktable.org / GitHub release

darktable version

5.4.1

What OS are you using?

Mac

What is the version of your OS?

Mac OS Tahoe

Describe your system

No response

Are you using OpenCL GPU in darktable?

No

If yes, what is the GPU card and driver?

No response

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

No response

Start by locating darktable's framing module and its tooltip text, then reproduce the 1000x500 export with scale 1, basis auto, and constant border using the percentages in the report. Compare the resulting dimensions with the expected per-side values and clarify whether the calculation or only the tooltip is incorrect; done means the behavior and description agree.