Hi,
From the commit message:
Intel OpenGL drivers have an issue where the results of a series of glBlitFramebuffer() can delay updating the display, when we use GDK_GL=always, which is manifested when attempting to enter text in text boxes.
This attempts to work around this issue by requiring a glFlush() call and a retry to the same glBlitFramebuffer() calls to avoid delays in keystrokes when using GDK_GL=always and when not using libANGLE OpenGL/ES emulation, when an Intel OpenGL driver is being used.
Fixes issue #3487 (closed)
Special thanks to @carrotIndustries for the analysis and coming up with a workaround, which this MR is based upon. It may the best we can do as this is most likely a driver-related issue.
With blessings, thank you!