Determine if nuget source name is case-sensitive and ensure disable and other uses works properly given that

[asherber]

Details about Problem

NuGet product used (NuGet.exe | VS UI | Package Manager Console | dotnet.exe): nuget.exe

NuGet version (x.x.x.xxx): 5.2.0.6090

dotnet.exe --version (if appropriate):

VS version (if appropriate):

OS version (i.e. win10 v1607 (14393.321)): win10 v1709 (16299.1268)

Worked before? If so, with which NuGet version: Don't know

Detailed repro steps so we can see the same problem

1. nuget sources add -name FOO -source https://example.com
2. nuget sources list (confirm new source is there)
3. nuget sources disable -name foo (nuget reports Package source with Name: foo disabled successfully.)
4. nuget sources list (source is still enabled!)
5. nuget sources disable -name FOO (nuget reports Package source with Name: foo disabled successfully.)
6. nuget sources list (source is disabled)

Note that nuget sources remove -name foo works just fine to remove a source whose name is FOO.

[kartheekp-ms]

Noticed that this issue was fixed in nuget.exe 4.8.2 version and broken in later releases.

[rrelyea]

Looked into this a bit. Looks like nuget sources disable -name foo will persist a disabled package source. However, it looks like packageSource FOO and disabledPackageSource foo are not found to match...so our system treats FOO as enabled.

Haven't looked at pre-4.9 behavior. (@kartheekp-ms said that 4.8.2 worked), but 4.9 is where we did major config file (setting) system enhancements.
Doing work for dotnet nuget disable source now... won't address this as part of that work, but we should fix.