windows-specific absolute link check

pkg/oci/containerize.go

@@ -211,7 +211,7 @@ func validateLink(root, path string, info os.FileInfo) error {
 	}
 
 	// Calculate the actual target of the link
-	// (relative to our current working directory)
+	// (relative to the parent of the symlink)
 	lnkTgt := filepath.Join(filepath.Dir(path), tgt)
 
 	// Calculate the relative path from the function's root to

pkg/oci/containerize_test.go

@@ -3,6 +3,7 @@ package oci
 import (
 	"os"
 	"path/filepath"
+	"runtime"
 	"testing"
 )
 
@@ -40,4 +41,18 @@ func Test_validateLink(t *testing.T) {
 			}
 		})
 	}
+	// Run a windows-specific absolute path test
+	// Note this technically succeeds on unix systems, but wrapping in
+	// an runtime check seems like a good idea to make it more clear.
+	if runtime.GOOS != "windows" {
+		path := "c://some/absolute/path"
+		info, err := os.Lstat(path)
+		if err != nil {
+			t.Fatal(err)
+		}
+		err = validateLink(root, path, info)
+		if err == nil {
+			t.Fatal("absolute path should be invalid on windows")
+		}
+	}
 }