[core] node: Correctly use custom size for non-parallelized nodes

Author: cbentejac

meshroom/core/node.py

@@ -2216,7 +2216,10 @@ def _resetChunks(self):
         self._chunks.setObjectList([])
         # Recreate list with reset values (1 chunk or the static size)
         if not self.isParallelized:
-            self.setSize(1)
+            if not self.nodeDesc.size:
+                self.setSize(1)
+            else:
+                self.setSize(self.nodeDesc.size.computeSize(self))
             self._chunks.setObjectList([NodeChunk(self, desc.Range())])
             self._chunks[0].statusChanged.connect(self.globalStatusChanged)
             self._chunksCreated = True