unit: make UNIT() cast function deal with NULL pointers

Fixes: #10681
2018-11-08 10:47:08 +01:00
parent 8d2411f693
commit bbf1120623
1 changed files with 6 additions and 1 deletions
@@ -582,7 +582,12 @@ extern const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX];
        }

 /* For casting the various unit types into a unit */
-#define UNIT(u) (&(u)->meta)
+#define UNIT(u)                                         \
+        ({                                              \
+                typeof(u) _u_ = (u);                    \
+                Unit *_w_ = _u_ ? &(_u_)->meta : NULL;  \
+                _w_;                                    \
+        })

 #define UNIT_HAS_EXEC_CONTEXT(u) (UNIT_VTABLE(u)->exec_context_offset > 0)
 #define UNIT_HAS_CGROUP_CONTEXT(u) (UNIT_VTABLE(u)->cgroup_context_offset > 0)