Saving a script file under a different name results in loss of colorization #1944

Saving a script file under a different name results in loss of colorization

Repro steps

Provide the steps required to reproduce the problem

1. Take script1.fsx containing some F# code. Observe its colors

2. Save it as script2.fsx. Observe its colors

Expected behavior

Colorized in both cases

Actual behavior

Colorized only prior to the save-as operation

Known workarounds

close/open the file