Avoid false positives on egl extension matching

Due to the strstr prefix match EGL_EXT_foo would be incorrectly matched
if EGL_EXT_foobar would be available but not foo.

This doesn't matter for the currently checked extensions but will matter
for EGL_EXT_image_dma_buf_import_modifiers vs
EGL_EXT_image_dma_buf_import

Code borrowed from weston
This commit is contained in:
Guido Günther 2018-02-28 18:21:34 +01:00
parent 73045a7d9d
commit d9f2e90df6

View File

@ -83,6 +83,24 @@ static bool egl_get_config(EGLDisplay disp, EGLint *attribs, EGLConfig *out,
return false;
}
static bool check_egl_ext(const char *egl_exts, const char *ext) {
size_t extlen = strlen(ext);
const char *end = egl_exts + strlen(egl_exts);
while (egl_exts < end) {
if (*egl_exts == ' ') {
egl_exts++;
continue;
}
size_t n = strcspn(egl_exts, " ");
if (n == extlen && strncmp(ext, egl_exts, n) == 0) {
return true;
}
egl_exts += n;
}
return false;
}
bool wlr_egl_init(struct wlr_egl *egl, EGLenum platform, void *remote_display,
EGLint *config_attribs, EGLint visual_id) {
if (!load_glapi()) {
@ -137,17 +155,17 @@ bool wlr_egl_init(struct wlr_egl *egl, EGLenum platform, void *remote_display,
wlr_log(L_INFO, "GL vendor: %s", glGetString(GL_VENDOR));
wlr_log(L_INFO, "Supported OpenGL ES extensions: %s", egl->gl_exts_str);
if (strstr(egl->egl_exts_str, "EGL_WL_bind_wayland_display") == NULL ||
strstr(egl->egl_exts_str, "EGL_KHR_image_base") == NULL) {
if (!check_egl_ext(egl->egl_exts_str, "EGL_WL_bind_wayland_display") ||
!check_egl_ext(egl->egl_exts_str, "EGL_KHR_image_base")) {
wlr_log(L_ERROR, "Required egl extensions not supported");
goto error;
}
egl->egl_exts.buffer_age =
strstr(egl->egl_exts_str, "EGL_EXT_buffer_age") != NULL;
check_egl_ext(egl->egl_exts_str, "EGL_EXT_buffer_age");
egl->egl_exts.swap_buffers_with_damage =
strstr(egl->egl_exts_str, "EGL_EXT_swap_buffers_with_damage") != NULL ||
strstr(egl->egl_exts_str, "EGL_KHR_swap_buffers_with_damage") != NULL;
check_egl_ext(egl->egl_exts_str, "EGL_EXT_swap_buffers_with_damage") ||
check_egl_ext(egl->egl_exts_str, "EGL_KHR_swap_buffers_with_damage");
return true;