Eric Wasylishen
The patch makes StartTextInput/StopTextInput call Xutf8ResetIC ( https://www.x.org/releases/X11R7.5/doc/man/man3/XmbResetIC.3.html ) on the XIC of all SDL windows.
This fixes my use case in Quakespasm (Ubuntu 16.04, system keyboard layout set to German. Type the '^' dead key, which opens Quakespasm's developer console and calls SDL_StartTextInput, then press 'e'. I expect the dead key to be ignored.)
Also, here is a patch for sdl2's "checkkeys" for testing this: https://bugzilla-attachments.libsdl.org/attachment.cgi?id=2451
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().