Fix: EEVEE-Next: ObjectKey

memset is not guaranteed to clear padding bytes,
which breaks the use of memcmp for comparison.

source/blender/draw/engines/eevee_next/eevee_sync.hh

@@ -49,10 +49,6 @@ class ObjectKey {
 
   ObjectKey(Object *ob, int sub_key = 0)
   {
-    /* Since we use `memcmp` for comparison,
-     * we have to ensure the padding bytes are initialized as well. */
-    memset(this, 0, sizeof(*this));
-
     ob_ = DEG_get_original_object(ob);
     hash_value_ = BLI_ghashutil_ptrhash(ob_);
 
@@ -81,12 +77,56 @@ class ObjectKey {
 
   bool operator<(const ObjectKey &k) const
   {
-    return memcmp(this, &k, sizeof(*this)) < 0;
+    if (hash_value_ != k.hash_value_) {
+      return hash_value_ < k.hash_value_;
+    }
+    if (ob_ != k.ob_) {
+      return (ob_ < k.ob_);
+    }
+    if (parent_ != k.parent_) {
+      return (parent_ < k.parent_);
+    }
+    if (sub_key_ != k.sub_key_) {
+      return (sub_key_ < k.sub_key_);
+    }
+    if (parent_) {
+      for (int i : IndexRange(MAX_DUPLI_RECUR)) {
+        if (id_[i] < k.id_[i]) {
+          return true;
+        }
+        if (id_[i] == INT_MAX) {
+          break;
+        }
+      }
+    }
+    return false;
   }
 
   bool operator==(const ObjectKey &k) const
   {
-    return memcmp(this, &k, sizeof(*this)) == 0;
+    if (hash_value_ != k.hash_value_) {
+      return false;
+    }
+    if (ob_ != k.ob_) {
+      return false;
+    }
+    if (parent_ != k.parent_) {
+      return false;
+    }
+    if (sub_key_ != k.sub_key_) {
+      return false;
+    }
+    if (parent_) {
+      for (int i : IndexRange(MAX_DUPLI_RECUR)) {
+        if (id_[i] != k.id_[i]) {
+          return false;
+        }
+        if (id_[i] == INT_MAX) {
+          break;
+        }
+      }
+    }
+    return true;
   }
 };