[rcore/rlgl] CloseWindow() segfaults if InitWindow() fails (with OpenGL 3.3)

[M374LX]

Issue description

If raylib is built with OpenGL 3.3 but this OpenGL version is not supported by the system (as might be the case of an old GPU), calling CloseWindow() after InitWindow() results in a segfault.

Apparently, the segfault happens inside rlglClose(), which is called from CloseWindow().

The segfault seems to happen only with SetTraceLogLevel(LOG_NONE). With SetTraceLogLevel(LOG_ALL), however, the output is:

INFO: Initializing raylib 4.6-dev
INFO: Supported raylib modules:
INFO:     > rcore:..... loaded (mandatory)
INFO:     > rlgl:...... loaded (mandatory)
INFO:     > rshapes:... loaded (optional)
INFO:     > rtextures:. loaded (optional)
INFO:     > rtext:..... loaded (optional)
INFO:     > rmodels:... loaded (optional)
INFO:     > raudio:.... loaded (optional)
WARNING: GLFW: Error: 65543 Description: GLX: Failed to create context: GLXBadFBConfig
WARNING: GLFW: Failed to initialize Window
FATAL: Failed to initialize Graphic Device

Everything works fine if raylib is built on the same system with OpenGL 2.1.

Environment

Void Linux on a Lenovo ThinkPad X200.

The output of lspci | grep VGA is:

00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)

These are the first lines of the output from glxinfo:

name of display: :1
display: :1  screen: 0
direct rendering: Yes
server glx vendor string: SGI
server glx version string: 1.4
server glx extensions:
    GLX_ARB_context_flush_control, GLX_ARB_create_context, 
    GLX_ARB_create_context_no_error, GLX_ARB_create_context_profile, 
    GLX_ARB_create_context_robustness, GLX_ARB_fbconfig_float, 
    GLX_ARB_framebuffer_sRGB, GLX_ARB_multisample, 
    GLX_EXT_create_context_es2_profile, GLX_EXT_create_context_es_profile, 
    GLX_EXT_fbconfig_packed_float, GLX_EXT_framebuffer_sRGB, 
    GLX_EXT_get_drawable_type, GLX_EXT_libglvnd, GLX_EXT_no_config_context, 
    GLX_EXT_texture_from_pixmap, GLX_EXT_visual_info, GLX_EXT_visual_rating, 
    GLX_INTEL_swap_event, GLX_MESA_copy_sub_buffer, GLX_OML_swap_method, 
    GLX_SGIS_multisample, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer, 
    GLX_SGIX_visual_select_group, GLX_SGI_make_current_read, 
    GLX_SGI_swap_control
client glx vendor string: Mesa Project and SGI
client glx version string: 1.4
client glx extensions:
    GLX_ARB_context_flush_control, GLX_ARB_create_context, 
    GLX_ARB_create_context_no_error, GLX_ARB_create_context_profile, 
    GLX_ARB_create_context_robustness, GLX_ARB_fbconfig_float, 
    GLX_ARB_framebuffer_sRGB, GLX_ARB_get_proc_address, GLX_ARB_multisample, 
    GLX_ATI_pixel_format_float, GLX_EXT_buffer_age, 
    GLX_EXT_create_context_es2_profile, GLX_EXT_create_context_es_profile, 
    GLX_EXT_fbconfig_packed_float, GLX_EXT_framebuffer_sRGB, 
    GLX_EXT_import_context, GLX_EXT_no_config_context, GLX_EXT_swap_control, 
    GLX_EXT_swap_control_tear, GLX_EXT_texture_from_pixmap, 
    GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_INTEL_swap_event, 
    GLX_MESA_copy_sub_buffer, GLX_MESA_query_renderer, GLX_MESA_swap_control, 
    GLX_NV_float_buffer, GLX_OML_swap_method, GLX_OML_sync_control, 
    GLX_SGIS_multisample, GLX_SGIX_fbconfig, GLX_SGIX_pbuffer, 
    GLX_SGIX_visual_select_group, GLX_SGI_make_current_read, 
    GLX_SGI_swap_control, GLX_SGI_video_sync
GLX version: 1.4
GLX extensions:
    GLX_ARB_context_flush_control, GLX_ARB_create_context, 
    GLX_ARB_create_context_no_error, GLX_ARB_create_context_profile, 
    GLX_ARB_create_context_robustness, GLX_ARB_fbconfig_float, 
    GLX_ARB_framebuffer_sRGB, GLX_ARB_get_proc_address, GLX_ARB_multisample, 
    GLX_EXT_buffer_age, GLX_EXT_create_context_es2_profile, 
    GLX_EXT_create_context_es_profile, GLX_EXT_fbconfig_packed_float, 
    GLX_EXT_framebuffer_sRGB, GLX_EXT_no_config_context, GLX_EXT_swap_control, 
    GLX_EXT_swap_control_tear, GLX_EXT_texture_from_pixmap, 
    GLX_EXT_visual_info, GLX_EXT_visual_rating, GLX_INTEL_swap_event, 
    GLX_MESA_copy_sub_buffer, GLX_MESA_query_renderer, GLX_MESA_swap_control, 
    GLX_OML_swap_method, GLX_OML_sync_control, GLX_SGIS_multisample, 
    GLX_SGIX_fbconfig, GLX_SGIX_pbuffer, GLX_SGIX_visual_select_group, 
    GLX_SGI_make_current_read, GLX_SGI_swap_control, GLX_SGI_video_sync
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: Intel (0x8086)
    Device: Mesa Mobile Intel® GM45 Express Chipset (CTG) (0x2a42)
    Version: 23.1.3
    Accelerated: yes
    Video memory: 1536MB
    Unified memory: yes
    Preferred profile: compat (0x2)
    Max core profile version: 0.0
    Max compat profile version: 2.1
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 2.0
OpenGL vendor string: Intel
OpenGL renderer string: Mesa Mobile Intel® GM45 Express Chipset (CTG)
OpenGL version string: 2.1 Mesa 23.1.3
OpenGL shading language version string: 1.20
OpenGL extensions:
    GL_3DFX_texture_compression_FXT1, GL_AMD_conservative_depth, 
    GL_AMD_performance_monitor, GL_AMD_seamless_cubemap_per_texture, 
    GL_AMD_shader_trinary_minmax, GL_ANGLE_texture_compression_dxt3, 
    GL_ANGLE_texture_compression_dxt5, GL_APPLE_packed_pixels, 
    GL_ARB_ES2_compatibility, GL_ARB_arrays_of_arrays, GL_ARB_base_instance, 
    GL_ARB_blend_func_extended, GL_ARB_buffer_storage, 
    GL_ARB_clear_buffer_object, GL_ARB_clear_texture, GL_ARB_clip_control, 
    GL_ARB_color_buffer_float, GL_ARB_compressed_texture_pixel_storage, 
    GL_ARB_conservative_depth, GL_ARB_copy_buffer, GL_ARB_copy_image, 
    GL_ARB_debug_output, GL_ARB_depth_buffer_float, GL_ARB_depth_clamp, 
    GL_ARB_depth_texture, GL_ARB_draw_buffers, 
    GL_ARB_draw_elements_base_vertex, GL_ARB_draw_instanced, 
    GL_ARB_explicit_attrib_location, GL_ARB_explicit_uniform_location, 
    GL_ARB_fragment_coord_conventions, GL_ARB_fragment_program, 
    GL_ARB_fragment_program_shadow, GL_ARB_fragment_shader, 
    GL_ARB_framebuffer_object, GL_ARB_framebuffer_sRGB, 
    GL_ARB_get_program_binary, GL_ARB_get_texture_sub_image, 
    GL_ARB_half_float_pixel, GL_ARB_half_float_vertex, 
    GL_ARB_instanced_arrays, GL_ARB_internalformat_query, 
    GL_ARB_internalformat_query2, GL_ARB_invalidate_subdata, 
    GL_ARB_map_buffer_alignment, GL_ARB_map_buffer_range, GL_ARB_multi_bind, 
    GL_ARB_multisample, GL_ARB_multitexture, GL_ARB_occlusion_query, 
    GL_ARB_occlusion_query2, GL_ARB_parallel_shader_compile, 
    GL_ARB_pixel_buffer_object, GL_ARB_point_parameters, GL_ARB_point_sprite, 
    GL_ARB_polygon_offset_clamp, GL_ARB_program_interface_query, 
    GL_ARB_provoking_vertex, GL_ARB_robustness, GL_ARB_sampler_objects, 
    GL_ARB_seamless_cube_map, GL_ARB_seamless_cubemap_per_texture, 
    GL_ARB_separate_shader_objects, GL_ARB_shader_bit_encoding, 
    GL_ARB_shader_group_vote, GL_ARB_shader_objects, 
    GL_ARB_shader_texture_lod, GL_ARB_shading_language_100, 
    GL_ARB_shading_language_420pack, GL_ARB_shading_language_include, 
    GL_ARB_shading_language_packing, GL_ARB_shadow, GL_ARB_sync, 
    GL_ARB_texture_barrier, GL_ARB_texture_border_clamp, 
    GL_ARB_texture_compression, GL_ARB_texture_compression_bptc, 
    GL_ARB_texture_compression_rgtc, GL_ARB_texture_cube_map, 
    GL_ARB_texture_env_add, GL_ARB_texture_env_combine, 
    GL_ARB_texture_env_crossbar, GL_ARB_texture_env_dot3, 
    GL_ARB_texture_filter_anisotropic, GL_ARB_texture_float, 
    GL_ARB_texture_mirror_clamp_to_edge, GL_ARB_texture_mirrored_repeat, 
    GL_ARB_texture_non_power_of_two, GL_ARB_texture_query_levels, 
    GL_ARB_texture_rectangle, GL_ARB_texture_rg, GL_ARB_texture_rgb10_a2ui, 
    GL_ARB_texture_storage, GL_ARB_texture_swizzle, GL_ARB_transpose_matrix, 
    GL_ARB_vertex_array_bgra, GL_ARB_vertex_array_object, 
    GL_ARB_vertex_attrib_binding, GL_ARB_vertex_buffer_object, 
    GL_ARB_vertex_program, GL_ARB_vertex_shader, 
    GL_ARB_vertex_type_10f_11f_11f_rev, GL_ARB_vertex_type_2_10_10_10_rev, 
    GL_ARB_window_pos, GL_ATI_blend_equation_separate, GL_ATI_draw_buffers, 
    GL_ATI_fragment_shader, GL_ATI_separate_stencil, 
    GL_ATI_texture_compression_3dc, GL_ATI_texture_env_combine3, 
    GL_ATI_texture_float, GL_EXT_EGL_image_storage, GL_EXT_EGL_sync, 
    GL_EXT_abgr, GL_EXT_bgra, GL_EXT_blend_color, 
    GL_EXT_blend_equation_separate, GL_EXT_blend_func_separate, 
    GL_EXT_blend_minmax, GL_EXT_blend_subtract, GL_EXT_compiled_vertex_array, 
    GL_EXT_copy_texture, GL_EXT_debug_label, 
    GL_EXT_demote_to_helper_invocation, GL_EXT_direct_state_access, 
    GL_EXT_draw_buffers2, GL_EXT_draw_instanced, GL_EXT_draw_range_elements, 
    GL_EXT_fog_coord, GL_EXT_framebuffer_blit, GL_EXT_framebuffer_object, 
    GL_EXT_framebuffer_sRGB, GL_EXT_gpu_program_parameters, 
    GL_EXT_gpu_shader4, GL_EXT_multi_draw_arrays, GL_EXT_packed_depth_stencil, 
    GL_EXT_packed_float, GL_EXT_packed_pixels, GL_EXT_pixel_buffer_object, 
    GL_EXT_point_parameters, GL_EXT_polygon_offset_clamp, 
    GL_EXT_provoking_vertex, GL_EXT_rescale_normal, GL_EXT_secondary_color, 
    GL_EXT_semaphore, GL_EXT_semaphore_fd, GL_EXT_separate_specular_color, 
    GL_EXT_shader_framebuffer_fetch_non_coherent, GL_EXT_shader_integer_mix, 
    GL_EXT_shadow_funcs, GL_EXT_stencil_two_side, GL_EXT_stencil_wrap, 
    GL_EXT_subtexture, GL_EXT_texture, GL_EXT_texture3D, 
    GL_EXT_texture_array, GL_EXT_texture_buffer_object, 
    GL_EXT_texture_compression_dxt1, GL_EXT_texture_compression_rgtc, 
    GL_EXT_texture_compression_s3tc, GL_EXT_texture_cube_map, 
    GL_EXT_texture_edge_clamp, GL_EXT_texture_env_add, 
    GL_EXT_texture_env_combine, GL_EXT_texture_env_dot3, 
    GL_EXT_texture_filter_anisotropic, GL_EXT_texture_integer, 
    GL_EXT_texture_lod_bias, GL_EXT_texture_object, GL_EXT_texture_rectangle, 
    GL_EXT_texture_sRGB, GL_EXT_texture_sRGB_R8, GL_EXT_texture_sRGB_decode, 
    GL_EXT_texture_shared_exponent, GL_EXT_texture_snorm, 
    GL_EXT_texture_swizzle, GL_EXT_vertex_array, GL_EXT_vertex_array_bgra, 
    GL_IBM_multimode_draw_arrays, GL_IBM_rasterpos_clip, 
    GL_IBM_texture_mirrored_repeat, GL_INGR_blend_func_separate, 
    GL_INTEL_performance_query, GL_KHR_blend_equation_advanced, 
    GL_KHR_context_flush_control, GL_KHR_debug, GL_KHR_no_error, 
    GL_KHR_parallel_shader_compile, GL_KHR_texture_compression_astc_ldr, 
    GL_KHR_texture_compression_astc_sliced_3d, GL_MESA_pack_invert, 
    GL_MESA_shader_integer_functions, GL_MESA_texture_signed_rgba, 
    GL_MESA_window_pos, GL_NV_ES1_1_compatibility, GL_NV_blend_square, 
    GL_NV_conditional_render, GL_NV_copy_image, GL_NV_depth_clamp, 
    GL_NV_fog_distance, GL_NV_half_float, GL_NV_light_max_exponent, 
    GL_NV_packed_depth_stencil, GL_NV_primitive_restart, 
    GL_NV_texgen_reflection, GL_NV_texture_barrier, 
    GL_NV_texture_env_combine4, GL_NV_texture_rectangle, GL_OES_EGL_image, 
    GL_OES_read_format, GL_S3_s3tc, GL_SGIS_generate_mipmap, 
    GL_SGIS_texture_border_clamp, GL_SGIS_texture_edge_clamp, 
    GL_SGIS_texture_lod, GL_SUN_multi_draw_arrays

OpenGL ES profile version string: OpenGL ES 2.0 Mesa 23.1.3
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 1.0.16
OpenGL ES profile extensions:
    GL_AMD_performance_monitor, GL_ANGLE_pack_reverse_row_order, 
    GL_ANGLE_texture_compression_dxt3, GL_ANGLE_texture_compression_dxt5, 
    GL_APPLE_texture_max_level, GL_EXT_blend_func_extended, 
    GL_EXT_blend_minmax, GL_EXT_clip_control, GL_EXT_color_buffer_half_float, 
    GL_EXT_compressed_ETC1_RGB8_sub_texture, GL_EXT_debug_label, 
    GL_EXT_demote_to_helper_invocation, GL_EXT_depth_clamp, 
    GL_EXT_discard_framebuffer, GL_EXT_draw_buffers, 
    GL_EXT_draw_elements_base_vertex, GL_EXT_draw_instanced, 
    GL_EXT_frag_depth, GL_EXT_instanced_arrays, GL_EXT_map_buffer_range, 
    GL_EXT_multi_draw_arrays, GL_EXT_occlusion_query_boolean, 
    GL_EXT_polygon_offset_clamp, GL_EXT_read_format_bgra, GL_EXT_semaphore, 
    GL_EXT_semaphore_fd, GL_EXT_separate_shader_objects, 
    GL_EXT_shader_framebuffer_fetch_non_coherent, GL_EXT_texture_border_clamp, 
    GL_EXT_texture_compression_dxt1, GL_EXT_texture_compression_s3tc, 
    GL_EXT_texture_compression_s3tc_srgb, GL_EXT_texture_filter_anisotropic, 
    GL_EXT_texture_format_BGRA8888, GL_EXT_texture_mirror_clamp_to_edge, 
    GL_EXT_texture_rg, GL_EXT_texture_type_2_10_10_10_REV, 
    GL_EXT_unpack_subimage, GL_INTEL_blackhole_render, 
    GL_INTEL_performance_query, GL_KHR_blend_equation_advanced, 
    GL_KHR_context_flush_control, GL_KHR_debug, GL_KHR_no_error, 
    GL_KHR_parallel_shader_compile, GL_KHR_texture_compression_astc_ldr, 
    GL_KHR_texture_compression_astc_sliced_3d, GL_MESA_bgra, 
    GL_NV_conditional_render, GL_NV_draw_buffers, GL_NV_fbo_color_attachments, 
    GL_NV_generate_mipmap_sRGB, GL_NV_pack_subimage, 
    GL_NV_pixel_buffer_object, GL_NV_read_buffer, GL_NV_read_depth, 
    GL_NV_read_depth_stencil, GL_NV_read_stencil, GL_OES_EGL_image, 
    GL_OES_EGL_image_external, GL_OES_EGL_sync, 
    GL_OES_compressed_ETC1_RGB8_texture, GL_OES_depth24, GL_OES_depth_texture, 
    GL_OES_depth_texture_cube_map, GL_OES_draw_elements_base_vertex, 
    GL_OES_element_index_uint, GL_OES_fbo_render_mipmap, 
    GL_OES_get_program_binary, GL_OES_mapbuffer, GL_OES_packed_depth_stencil, 
    GL_OES_required_internalformat, GL_OES_rgb8_rgba8, 
    GL_OES_standard_derivatives, GL_OES_stencil8, GL_OES_surfaceless_context, 
    GL_OES_texture_3D, GL_OES_texture_border_clamp, GL_OES_texture_float, 
    GL_OES_texture_float_linear, GL_OES_texture_half_float, 
    GL_OES_texture_half_float_linear, GL_OES_texture_npot, 
    GL_OES_vertex_array_object, GL_OES_vertex_half_float

Code Example

#include "raylib.h"

int main()
{
	SetTraceLogLevel(LOG_ALL);
	InitWindow(0, 0, "Test");
	CloseWindow();
}

@M374LX I could be wrong, but I think that's expected. As far as I understand you have to target the lowest OpenGL version you want to support (e.g.: I compile with OpenGL 2.1 to also support older hardware).

[raysan5]

@M374LX @ubkp yes, that's the expected behaviour.

[M374LX]

Compiling with a lower OpenGL version is fine, but I still think a segfault is never the expected behavior and rlglClose() should check if the resources were correctly allocated before trying to free them.

@M374LX That could be related to rlglClose() only having any content if raylib was compiled with GRAPHICS_API_OPENGL_33 or GRAPHICS_API_OPENGL_ES2 (L2158-L2165) support.

If it was, but the program/game is executed on local hardware without it, when it reaches rlglClose() it will probably try to execute rlUnloadRenderBatch (L2654) and rlUnloadShaderDefault(L4649) which the calls (I think) are not present on the previous OpenGL versions, thus, likely causing that crash.

Edit: In this scenario, I think that, in practice, the program/game would crash way earlier when it attempted to start drawing. To reliably handle that I think it would be necessary to detect the OpenGL version on runtime, but I don't think there are any plans for that.

[M374LX]

A possible solution is to add if (!CORE.Window.ready) return; to the start of CloseWindow(), but we need to check if no necessary deinitialization would be missed.

@M374LX I think it depends until which point the program/game would reach with the unsupported OpenGL version. If it manages to reach L848, then it would still crash there.

But, IMHO, I don't think this is much of a problem.