Fix logger test.

src/tests/log.rs

@@ -1,13 +1,24 @@
+type LogFn = unsafe extern "C" fn(*const libc::c_char);
+
+unsafe extern "C" fn test_info_callback(_msg: *const libc::c_char) {}
+unsafe extern "C" fn test_error_callback(_msg: *const libc::c_char) {}
+
 #[test]
 fn can_set_logger() {
     crate::set_logger(crate::LoggerType::Custom {
         info: test_info_callback,
         error: test_error_callback,
     });
-    assert!(unsafe { crate::jack_sys::jack_info_callback } == Some(test_info_callback),);
-    assert!(unsafe { crate::jack_sys::jack_error_callback } == Some(test_error_callback),);
+    #[cfg(feature = "dynamic_loading")]
+    unsafe {
+        let lib = jack_sys::library().unwrap();
+        assert!(**lib.get::<*const LogFn>(b"jack_info_callback").unwrap() == test_info_callback);
+        assert!(**lib.get::<*const LogFn>(b"jack_error_callback").unwrap() == test_error_callback);
+    }
+    #[cfg(not(feature = "dynamic_loading"))]
+    {
+        assert!(unsafe { crate::jack_sys::jack_info_callback } == Some(test_info_callback),);
+        assert!(unsafe { crate::jack_sys::jack_error_callback } == Some(test_error_callback),);
+    }
     super::log_to_stdio(); // Revert to enable debugging in other tests.
 }
-
-unsafe extern "C" fn test_info_callback(_msg: *const libc::c_char) {}
-unsafe extern "C" fn test_error_callback(_msg: *const libc::c_char) {}