1. Move cursor to the middle of the address.
2. Mouse button down.
3. Move cursor to the side, possibly outside of the address field.
4. Mouse button up.

1. Move cursor to the middle of the address.
2. Mouse button down, mouse button up, mouse button down.
3. Move cursor to the side, outside of the address field.
4. Mouse button up.

One can select whole "words"/segments in the address field by double-click-dragging and then releasing; just like a regular selection is click-dragging and then releasing. The bug is when you double-click-drag and then release the mouse button _outside of the address field_. The "mouse up" event fails to stop selecting text, it makes text blue like if you still held the button down. To clarify, here's pseudo code of how to select some text (works): 1. Move cursor to the middle of the address. 2. Mouse button down. 3. Move cursor to the side, possibly outside of the address field. 4. Mouse button up. Result: you selected half of the address, and can now e.g. copy it. However, pseudo code of what does NOT work: 1. Move cursor to the middle of the address. 2. Mouse button down, mouse button up, mouse button down. 3. Move cursor to the side, outside of the address field. 4. Mouse button up. Result: as you move the cursor around, you are still in the process of changing the selection. I'm on Firefox Developer edition `70.0b7 (64-bit)`.