Handle when no "direct" packages are changed (#37599)

* ensure the default isn't "scan the entire repo"

Author: scbedd

eng/pipelines/templates/jobs/ci.yml

@@ -138,7 +138,7 @@ jobs:
       parameters:
         BuildTargetingString: ${{ parameters.BuildTargetingString }}
         PackagePropertiesFolder: $(Build.ArtifactStagingDirectory)/PackageInfo
-        IncludeIndirect: true
+        IncludeIndirect: false
 
     - template: /eng/pipelines/templates/steps/build-extended-artifacts.yml
       parameters:
@@ -170,7 +170,7 @@ jobs:
       parameters:
         BuildTargetingString: ${{ parameters.BuildTargetingString }}
         PackagePropertiesFolder: $(Build.ArtifactStagingDirectory)/PackageInfo
-        IncludeIndirect: true
+        IncludeIndirect: false
 
     - template: ../steps/build-extended-artifacts.yml
       parameters:

eng/pipelines/templates/steps/resolve-package-targeting.yml

@@ -33,6 +33,12 @@ steps:
           }
 
           $setting = $packageProperties -join ","
+
+          # in case we don't expect any packages, we should set the variable to null, which will match NO packages and cause whatever the check
+          # is to skip with exit 0 (which is what we want!)
+          if (-not $setting) {
+            $setting = "null"
+          }
         }
       }