ddnet PR #12467: fix map_render GLEW/CI build + InitError==-2 shutdown crash

12467-ci-glew-fix.patch

diff --git a/CMakeLists.txt b/CMakeLists.txt
index da16f4905..a509c9961 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3190,7 +3190,7 @@ if(TOOLS)
       endif()
       if(TOOL MATCHES "^map_render$")
         list(APPEND TOOL_INCLUDE_DIRS ${PNG_INCLUDE_DIRS} ${FREETYPE_INCLUDE_DIRS} ${GLEW_INCLUDE_DIRS})
-        list(APPEND TOOL_DEPS $<TARGET_OBJECTS:engine-gfx>)
+        list(APPEND TOOL_DEPS $<TARGET_OBJECTS:engine-gfx> ${GLEW_DEP})
         list(APPEND TOOL_LIBS ${PNG_LIBRARIES} ${FREETYPE_LIBRARIES} ${GLEW_LIBRARIES} ${CMAKE_DL_LIBS} ${EGL_LIBRARY} ${OPENGL_gl_LIBRARY})
       endif()
       set(EXCLUDE_FROM_ALL)
@@ -3226,9 +3226,13 @@ if(TOOLS)
           src/game/map/render_map.cpp
           src/game/map/render_component.cpp
           src/game/map/envelope_extrema.cpp
+          ${PROJECT_BINARY_DIR}/src/generated/client_data.h
         )
         target_include_directories(map_render PRIVATE ${PROJECT_BINARY_DIR})
         target_compile_definitions(map_render PRIVATE BACKEND_NO_SDL)
+        if(GLEW_BUNDLED)
+          target_compile_definitions(map_render PRIVATE CONF_GLEW_HAS_CONTEXT_INIT)
+        endif()
       endif()
       list(APPEND TARGETS_TOOLS ${TOOL})
     endif()
diff --git a/src/engine/client/backend_egl.cpp b/src/engine/client/backend_egl.cpp
index 1fcf87b26..2d942a405 100644
--- a/src/engine/client/backend_egl.cpp
+++ b/src/engine/client/backend_egl.cpp
@@ -167,12 +167,23 @@ CGraphicsBackend_EGL::CGraphicsBackend_EGL(TTranslateFunc &&TranslateFunc) :
 static bool BackendInitGlew(int &GlewMajor, int &GlewMinor, int &GlewPatch)
 {
 	glewExperimental = GL_TRUE;
+#ifdef CONF_GLEW_HAS_CONTEXT_INIT
 	const GLenum InitResult = glewContextInit();
 	if(InitResult != GLEW_OK)
 	{
-		log_error("gfx", "Unable to init glew: %s", glewGetErrorString(InitResult));
+		log_error("gfx", "Unable to init glew (glewContextInit): %s", glewGetErrorString(InitResult));
 		return false;
 	}
+#else
+	const GLenum InitResult = glewInit();
+	// There is no GLX display when rendering headlessly through EGL, in which case glewInit
+	// has already initialized the context with glewContextInit internally.
+	if(InitResult != GLEW_OK && InitResult != GLEW_ERROR_NO_GLX_DISPLAY)
+	{
+		log_error("gfx", "Unable to init glew (glewInit): %s", glewGetErrorString(InitResult));
+		return false;
+	}
+#endif
 
 #ifdef GLEW_VERSION_4_6
 	if(GLEW_VERSION_4_6)
@@ -456,12 +467,16 @@ int CGraphicsBackend_EGL::InitOpenGL(int Width, int Height, int Flags, IStorage
 
 	if(InitError != 0)
 	{
-		CCommandProcessorFragment_GLBase::SCommand_Shutdown CmdShutdown;
 		CCommandBuffer CmdBuffer(1024, 512);
-		CmdBuffer.AddCommandUnsafe(CmdShutdown);
-		RunBuffer(&CmdBuffer);
-		WaitForIdle();
-		CmdBuffer.Reset();
+		if(InitError != -2)
+		{
+			// shutdown the context, as it might have been initialized
+			CCommandProcessorFragment_GLBase::SCommand_Shutdown CmdShutdown;
+			CmdBuffer.AddCommandUnsafe(CmdShutdown);
+			RunBuffer(&CmdBuffer);
+			WaitForIdle();
+			CmdBuffer.Reset();
+		}
 		StopProcessor();
 		delete m_pProcessor;
 		m_pProcessor = nullptr;