Corrupt NuGet.config is ignored by nuget

[yishaigalatzer]

example:

Create a console app
install jquery
Clean the packages folder

Drop the following content into a local nuget.config

<boo

run nuget.exe restore consoleapp.sln

Expected

Fail or warn

Actual

The invalid config is ignored and restore proceeds

Why does it matter?
Imaging the config file was pointing to a different repository, but it had a flaw where the XML was invalid. The restore will bring down incorrect packages or fail with a warning that the packages don't exist.

[yishaigalatzer]

Consider warning also for files without a configuration section. e.g.

<?xml version="1.0" encoding="utf-8"?>
<packageSources>
  <clear />
  <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
  <add key="azure" value="https://www.myget.org/F/azureadwebstacknightly/" />
</packageSources>

[csharpfritz]

Looks like a duplicate of #1302

Also reported on Twitter: https://twitter.com/devlead/status/684305178342731776

[yishaigalatzer]

Summary: Any invalid config file that should be picked up, but fails to load should be turned into an error message that shows both in the UI and commandline (both nuget.exe and xplat). The error should be meaningful and point to the filename/file path and location in the file.

This should work both for the scenario where you pass in a -configFile or the config file is on disk, see #1302 for another repro scenario.

[zhili1208]

it's fixed