Restore is case sensitive in weird ways

[blackdwarf]

When restoring projects that have P2P references and a meta-package that is of a wrong case, weird errors crop up during restore. The cause is that the library has a wrong case of the metapackage for NETStandard.Library (NetStandard.Library).

Repro

git clone https://github.com/bleroy/paynoattentiontothis/
git checkout 55771a3
cd GoldenCLI/test/TestLibrary
dotnet restore

Expected result

Restore succeeds.

Actual result

Restore fails with a lot of errors like the following:

Unable to satisfy conflicting requests for 'System.Security.Cryptography.Cng': System.Security.Cryptography.Cng (>= 4.1.0-rc2-24027) (via package/System.Security.Cryptography.X509Certificates 4.1.0-rc2-24027), System.Security.Cryptography.Cng (>= 4.1.0-rc2-24027) (via package/System.Security.Cryptography.X509Certificates 4.1.0-rc2-24027), System.Security.Cryptography.Cng (>= 4.1.0-rc2-24027) (via package/System.Security.Cryptography.X509Certificates 4.1.0-rc2-24027), System.Security.Cryptography.Cng (>= 4.1.0-rc2-24027) (via package/System.Security.Cryptography.X509Certificates 4.1.0-rc2-24027)
    Unable to satisfy conflicting requests for 'System.Security.Cryptography.Csp': System.Security.Cryptography.Csp (>= 4.0.0-rc2-24027) (via package/System.Security.Cryptography.X509Certificates 4.1.0-rc2-24027), System.Security.Cryptography.Csp (>= 4.0.0-rc2-24027) (via package/System.Security.Cryptography.X509Certificates 4.1.0-rc2-24027), System.Security.Cryptography.Csp (>= 4.0.0-rc2-24027) (via package/System.Security.Cryptography.X509Certificates 4.1.0-rc2-24027), System.Security.Cryptography.Csp (>= 4.0.0-rc2-24027) (via package/System.Security.Cryptography.X509Certificates 4.1.0-rc2-24027)
    Unable to satisfy conflicting requests for 'Microsoft.NETCore.Targets': Microsoft.NETCore.Targets (>= 1.0.1-rc2-24027) (via package/Microsoft.NETCore.Platforms 1.0.1-rc2-24027), Microsoft.NETCore.Targets (>= 1.0.1-rc2-24027) (via package/Microsoft.NETCore.Platforms 1.0.1-rc2-24027), Microsoft.NETCore.Targets (>= 1.0.1-rc2-24027) (via package/Microsoft.NETCore.Platforms 1.0.1-rc2-24027), Microsoft.NETCore.Targets (>= 1.0.1-rc2-24027) (via package/Microsoft.NETCore.Platforms 1.0.1-rc2-24027)

/cc @yishaigalatzer @emgarten @bleroy @cartermp

[yishaigalatzer]

CC @joelverhagen should this be fixed by lowercase paths feature you are working on?

[joelverhagen]

I've reproduced this even with my case insensitive changes (which mostly focused on the file system). I've also trimmed down the repro to a minimal graph, as it seems to be a restore graph issue:
simple.zip