HGLRC rc1 = wglCreateContext(hDC);
HGLRC rc2 = wglCreateContext(hDC);

wglMakeCurrent(hDC, rc1);
// generate some texture names
GLuint texs[10];
GLuint tex = 0;
glGenTextures(10, texs);

// this gives us 8
tex = texs[7];

// bind it and reserve some space
glBindTexture(GL_TEXTURE_2D, tex);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 4, 4, 0, GL_RGB, GL_UNSIGNED_BYTE, 0);

// share resources with other context
wglShareLists(rc1, rc2);

// switch to the second context
wglMakeCurrent(hDC, rc2);
// tex belongs to this context too
assert(glIsTexture(tex));
// delete tex from the second context
glDeleteTextures(1, &tex);

// switch back
wglMakeCurrent(hDC, rc1);
// tex is no longer a texture (even in rc1)
assert(!glIsTexture(tex));

GLint tex2;
// get the binding
glGetIntegerv(GL_TEXTURE_BINDING_2D, &tex2);
// tex2 comes back as 8
// it is not a texture
assert(!glIsTexture(tex2));

// trying to upload it...
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 4, 4, 0, GL_RGB, GL_UNSIGNED_BYTE, 0);
// still fails
assert(!glIsTexture(tex2));

// bind it again
glBindTexture(GL_TEXTURE_2D, tex2);
// now its all good!
assert(glIsTexture(tex2));