PCB layout - Create common ground connection for 5V signal and 12V power

For my board, which drives dc motor, I want to create a common ground that connects 5v gnd and 12V gnd, as shown in figure 1. The problem I am encountering, as shown in figure 2 is that eagle cad combines the two nets from each ground. After searching for answers, one possible solution is to use a zero ohm resistor between the two nets, as shown in figure 3. Is this the ideal way, to create a common ground?

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