Removing the egl-generic rendering platform from the supported list if

another platform is available

Author: mattkae

src/server/graphics/default_configuration.cpp

@@ -316,6 +316,29 @@ auto mir::DefaultServerConfiguration::the_rendering_platforms() ->
             else
             {
                 platform_modules = mir::graphics::rendering_modules_for_device(platforms, display_targets, dynamic_cast<mir::options::ProgramOption&>(*the_options()), the_console_services());
+
+                // In the case that we have more than one platform, we try and remove mir:egl-generic,
+                // since it is problematic. See https://github.com/MirServer/mir/issues/3112
+                // TODO: Remove me once a multi-rendering-platform paradigm is fully supported, and we
+                // don't just select the first (or last?) platform and use that everywhere.
+                if (platform_modules.size() > 1)
+                {
+                    auto it = platform_modules.begin();
+                    while (it != platform_modules.end())
+                    {
+                        auto describe_module = it->second->load_function<mg::DescribeModule>(
+                            "describe_graphics_module",
+                            MIR_SERVER_GRAPHICS_PLATFORM_VERSION);
+
+                        auto description = describe_module();
+                        if (strcmp(description->name, "mir:egl-generic") == 0)
+                        {
+                            platform_modules.erase(it);
+                            break;
+                        }
+                        it++;
+                    }
+                }
             }
 
             for (auto const& [device, platform]: platform_modules)