commit 8d5f91014a533fd261ede94ce2df41661f7113d0
author "Dmitry V. Levin" <ldv@altlinux.org> Sat Jan 04 11:03:04 2020 -0800
committer "Dmitry V. Levin" <ldv@altlinux.org> Sat Jan 04 11:03:04 2020 -0800
tree da165c27f2c2e5c9e4fd03375e6df8d4131b3d08
parent 887f98ae5d4cc59eca40505381b9df06a582e387

have_mitshm: use XShmQueryExtension to check for MIT-SHM extension
Do not try to guess MIT_SHM extension availability from the string
returned by XDisplayName, use the appropriate API instead.

This fixes SDL2 inside hasher.

src/video/x11/SDL_x11framebuffer.c

diff --git a/src/video/x11/SDL_x11framebuffer.c b/src/video/x11/SDL_x11framebuffer.c
index 1897c3b..1659adf 100644
--- a/src/video/x11/SDL_x11framebuffer.c
+++ b/src/video/x11/SDL_x11framebuffer.c
@@ -40,14 +40,10 @@
         return(X_handler(d,e));
 }
 
-static SDL_bool have_mitshm(void)
+static SDL_bool have_mitshm(Display *dpy)
 {
     /* Only use shared memory on local X servers */
-    if ( (SDL_strncmp(X11_XDisplayName(NULL), ":", 1) == 0) ||
-         (SDL_strncmp(X11_XDisplayName(NULL), "unix:", 5) == 0) ) {
-        return SDL_X11_HAVE_SHM;
-    }
-    return SDL_FALSE;
+    return X11_XShmQueryExtension(dpy) ? SDL_X11_HAVE_SHM : SDL_FALSE;
 }
 
 #endif /* !NO_SHARED_MEMORY */
@@ -86,7 +82,7 @@
 
     /* Create the actual image */
 #ifndef NO_SHARED_MEMORY
-    if (have_mitshm()) {
+    if (have_mitshm(display)) {
         XShmSegmentInfo *shminfo = &data->shminfo;
 
         shminfo->shmid = shmget(IPC_PRIVATE, window->h*(*pitch), IPC_CREAT | 0777);