Some warnings may be discarded using #load with forward slash path separators

[taylorwood]

I noticed this issue while reproducing #1126: using forward slashes in the path for #load "c:/temp/nada.fsx" suppressed the warning in FSI when it seems it shouldn't have.

https://github.com/Microsoft/visualfsharp/blob/master/src/fsharp/CompileOps.fs#L5001
The file path comparison doesn't "normalize" the path separators, so rootFilename still has forward slashes while m.FileName doesn't, and warnings later get filtered by isRootRange.

Repro steps

To reproduce, create a file, say C:\temp\nada.fsx containing

#nowarn "211"
#I "totally-non-existing-folder"

And then run the following in F# Interactive:

> #load "C:/temp/nada.fsx";;

Expected behavior

> #load "C:/temp/nada.fsx";;

[Loading C:\temp\nada.fsx]
C:\temp\nada.fsx(2,1): warning FS0211: The search directory 
    'C:\temp\totally-non-existing-folder' could not be found
namespace FSI_0002

I think the warning should've (erroneously, according to #1126 and #1239) appeared whether using backward or forward slashes with #load.

Actual behavior

> #load "C:/temp/nada.fsx";;

[Loading C:\temp\nada.fsx]

namespace FSI_0002

Warning doesn't appear as it does when using backslashes in path.

Known workarounds

Don't use forward slashes in #load paths.

Related information

The repro steps for this issue will no longer work if #1239 is merged, but I think the issue will still exist.

• Windows 10.0.10586
• master branch
• .NET 4
• Low severity?