Support option update if option's content is mixed with variable and literal text

[yiminghe]

Option update will fail if option's content is mixed with variable and literal text. for example:

https://jsfiddle.net/yiminghe/jw73ccu5/1/

pr will come soon.

[jimfb]

This is a valid bug, but I'm going to close this gh issue in favor of tracking this as #2620