Too bad. I only fixed SDL2. I cannot even find the SDL that we use.
Maybe it's time to build a version of dosbox that uses SDL2.
Hmm, looking, DosBoxes last release was 5 years back, so likely no SDL2 support though I didn't find build instructions.
There are forks such as DosBox-X,
https://dosbox-x.com/ which would be nice to have. Even it comes with an intree heavily modified SDL as well as support for SDL2. This one would be nice to have as it is expanded to run most DOS apps including Win9x.
There is also SDL3 now