src/java,desktop/share/legal/mesa3d.md refers to v4.1
even though the expectation is that we are using 5.0,
perhaps because the header file it references says 4.1
./unix/native/common/java2d/opengl/J2D_GL/glx.h
However if you look at the header file from Mesa v5.0,
available here :
https://mesa.freedesktop.org/archive/older-versions/5.x/
It says 4.1 .. so it just means that Mesa did not update
all their source files.
Note that the version of the header file in JDK is modified
to support Java2D .. it is not a verbatim copy of the original.
The fix for this touches nothing but the version number in
mesa.md.
It seems that the legal file should really be in
src/java,desktop/unix/legal/ but we'll fix that next time.