Check the correct buffer to detect change in the CtrlSFClose command

[vds2212]

This pull request intent to solve issue #350.

[dyng]

Thank you for your fix!

[vds2212]

Thanks for accepting it :-)

I also submitted three other pull request:

• one to make CtrlSF to be robust to change of working directory Use the working folder of the search to used it to open the result file. #345
• one to support alternative encoding, provided by rg Add support for the encoding flag. #348 and
• one to support backslash in pattern Don't escape backslash in patterns to allow backslash in patterns #347

Did you had the chance to have a look to it?
Is it something I can do to improve them or to make it easier for you to validate them?