Detect OSMesa errors

1 files changed, 11 insertions, 4 deletions

diff --git a/src/x11/headless.rs b/src/x11/headless.rs
index 71232e5..977305a 100644
--- a/src/x11/headless.rs
+++ b/src/x11/headless.rs
@@ -1,5 +1,5 @@
 use HeadlessRendererBuilder;
-use CreationError;
+use {CreationError, OsError};
 use libc;
 use std::{mem, ptr};
 use super::ffi;
@@ -18,16 +18,23 @@ impl HeadlessContext {
             height: builder.dimensions.1,
             buffer: Vec::from_elem(builder.dimensions.0 * builder.dimensions.1, unsafe { mem::uninitialized() }),
             context: unsafe {
-                // TODO: check errors
-                ffi::OSMesaCreateContext(0x1908, ptr::null())
+                let ctxt = ffi::OSMesaCreateContext(0x1908, ptr::null());
+                if ctxt.is_null() {
+                    return Err(OsError("OSMesaCreateContext failed".to_string()));
+                }
+                ctxt
             }
         })
     }
 
     pub unsafe fn make_current(&self) {
-        ffi::OSMesaMakeCurrent(self.context,
+        let ret = ffi::OSMesaMakeCurrent(self.context,
             self.buffer.as_ptr() as *mut libc::c_void,
             0x1401, self.width as libc::c_int, self.height as libc::c_int);
+
+        if ret == 0 {
+            panic!("OSMesaMakeCurrent failed")
+        }
     }
 
     pub fn get_proc_address(&self, addr: &str) -> *const () {