We are currently migrating Bugzilla to GitHub issues.
Any changes made to the bug tracker now will be lost, so please do not post new bugs or make changes to them.
When we're done, all bug URLs will redirect to their equivalent location on the new bug tracker.

Created attachment 1304 [details]
Self-contained test case.

SDL_GL_GetAttribute(SDL_GL_RED_SIZE) etc. fails for core profiles because it's using deprecated/removed OpenGL functionality. Here's a self-contained repro (I'm using mingw-w64 on Win7 x64, but the problem is universal):

C:\Temp\gcc>type meow.cpp
// g++ -DUSE_CORE_PROFILE -Wall -Wextra -mwindows meow.cpp -o meow.exe -lopengl32 -lSDL2 -limm32 -lole32 -loleaut32 -luuid -lversion -lwinmm -lmingw32 -lSDL2main

#include <stddef.h>
#include <fstream>
#include <GL/gl.h>
#include <SDL2/SDL.h>

struct Attribute {
    SDL_GLattr attr;
    int value;
    const char * name;
};

int main(int, char * []) {
    std::ofstream f("output.txt");

#ifdef USE_CORE_PROFILE
    f << "Using core profile.\n";
#else
    f << "Using compatibility profile.\n";
#endif

    if (SDL_Init(SDL_INIT_VIDEO) != 0) {
        f << "SDL_Init() failed!\n";
    }

    #define ATTRIB(ATTR, VALUE) { ATTR, VALUE, #ATTR }

    const Attribute attrs[] = {
        ATTRIB(  SDL_GL_RED_SIZE, 8),
        ATTRIB(SDL_GL_GREEN_SIZE, 8),
        ATTRIB( SDL_GL_BLUE_SIZE, 8),
        ATTRIB(SDL_GL_ALPHA_SIZE, 8),
        ATTRIB(SDL_GL_DEPTH_SIZE, 0),
        ATTRIB(SDL_GL_DOUBLEBUFFER, 1),
        ATTRIB(SDL_GL_ACCELERATED_VISUAL, 1),
        ATTRIB(SDL_GL_CONTEXT_MAJOR_VERSION, 4),
        ATTRIB(SDL_GL_CONTEXT_MINOR_VERSION, 3),
#ifdef USE_CORE_PROFILE
        ATTRIB(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE)
#else
        ATTRIB(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_COMPATIBILITY)
#endif
    };

    const size_t N = sizeof(attrs) / sizeof(attrs[0]);

    for (size_t i = 0; i < N; ++i) {
        if (SDL_GL_SetAttribute(attrs[i].attr, attrs[i].value) != 0) {
            f << "SDL_GL_SetAttribute() failed!\n";
        }
    }

    SDL_Window * window = SDL_CreateWindow("Meow", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1920, 1200, SDL_WINDOW_OPENGL);

    if (!window) {
        f << "SDL_CreateWindow() failed!\n";
    }

    SDL_GLContext context = SDL_GL_CreateContext(window);

    if (!context) {
        f << "SDL_GL_CreateContext() failed!\n";
    }

    for (size_t i = 0; i < N; ++i) {
        int val = 0;

        if (SDL_GL_GetAttribute(attrs[i].attr, &val) != 0) {
            f << "SDL_GL_GetAttribute(" << attrs[i].name << ") failed!\n";
            continue;
        }

        if (val != attrs[i].value) {
            f << "Unexpected attribute value!\n";
        }
    }

    if (glGetError() == GL_NO_ERROR) {
        f << "Done!\n";
    } else {
        f << "glGetError() recorded failure!\n";
    }

    SDL_GL_DeleteContext(context);
    SDL_DestroyWindow(window);
    SDL_Quit();
    return 0;
}

C:\Temp\gcc>g++ -Wall -Wextra -mwindows meow.cpp -o meow.exe -lopengl32 -lSDL2 -limm32 -lole32 -loleaut32 -luuid -lversion -lwinmm -lmingw32 -lSDL2main

C:\Temp\gcc>meow

C:\Temp\gcc>type output.txt
Using compatibility profile.
Done!

C:\Temp\gcc>g++ -DUSE_CORE_PROFILE -Wall -Wextra -mwindows meow.cpp -o meow.exe -lopengl32 -lSDL2 -limm32 -lole32 -loleaut32 -luuid -lversion -lwinmm -lmingw32 -lSDL2main

C:\Temp\gcc>meow

C:\Temp\gcc>type output.txt
Using core profile.
SDL_GL_GetAttribute(SDL_GL_RED_SIZE) failed!
SDL_GL_GetAttribute(SDL_GL_GREEN_SIZE) failed!
SDL_GL_GetAttribute(SDL_GL_BLUE_SIZE) failed!
SDL_GL_GetAttribute(SDL_GL_ALPHA_SIZE) failed!
SDL_GL_GetAttribute(SDL_GL_DEPTH_SIZE) failed!
Done!

The problem is in SDL_video.c, where SDL_GL_GetAttribute() calls glGetIntegerv() with GL_RED_BITS. As http://www.opengl.org/registry/doc/glspec43.compatibility.20130214.pdf explains in D.2.2 "Removed Features", page 790, this enum was removed:

"Context framebuffer size queries - RED_BITS, GREEN_BITS, BLUE_BITS, ALPHA_BITS, DEPTH_BITS, and STENCIL_BITS."

(STENCIL doesn't appear in my test because I'm not using it, but it is clearly also affected.)

The core-friendly way to query this information appears to be glGetFramebufferAttachmentParameteriv(), available since OpenGL 3.0: http://www.opengl.org/wiki/GLAPI/glGetFramebufferAttachmentParameter