Avoid imports of same name

This primarily benefits applyconfiguration-gen today, which accidentaly
got this behavior by including the local package name in imports, which
caused goimports to deconflict with it before removing it since it was
unused.  This commit effictively preserves that behavior now that we
will not be relying on goimports to add/rename/remove imports.

Co-authored-by: Tim Hockin <[email protected]>

Author: jpbetz

v2/generator/import_tracker.go

@@ -18,6 +18,7 @@ package generator
 
 import (
 	"go/token"
+	"path/filepath"
 	"strings"
 
 	"k8s.io/klog/v2"
@@ -45,7 +46,7 @@ import (
 func NewImportTrackerForPackage(local string, typesToAdd ...*types.Type) *namer.DefaultImportTracker {
 	tracker := namer.NewDefaultImportTracker(types.Name{Package: local})
 	tracker.IsInvalidType = func(*types.Type) bool { return false }
-	tracker.LocalName = func(name types.Name) string { return goTrackerLocalName(&tracker, name) }
+	tracker.LocalName = func(name types.Name) string { return goTrackerLocalName(&tracker, local, name) }
 	tracker.PrintImport = func(path, name string) string { return name + " \"" + path + "\"" }
 
 	tracker.AddTypes(typesToAdd...)
@@ -56,14 +57,15 @@ func NewImportTracker(typesToAdd ...*types.Type) *namer.DefaultImportTracker {
 	return NewImportTrackerForPackage("", typesToAdd...)
 }
 
-func goTrackerLocalName(tracker namer.ImportTracker, t types.Name) string {
+func goTrackerLocalName(tracker namer.ImportTracker, localPkg string, t types.Name) string {
 	path := t.Package
 
 	// Using backslashes in package names causes gengo to produce Go code which
 	// will not compile with the gc compiler. See the comment on GoSeperator.
 	if strings.ContainsRune(path, '\\') {
 		klog.Warningf("Warning: backslash used in import path '%v', this is unsupported.\n", path)
 	}
+	localLeaf := filepath.Base(localPkg)
 
 	dirs := strings.Split(path, namer.GoSeperator)
 	for n := len(dirs) - 1; n >= 0; n-- {
@@ -74,8 +76,13 @@ func goTrackerLocalName(tracker namer.ImportTracker, t types.Name) string {
 		// packages, but aren't legal go names. So we'll sanitize.
 		name = strings.ReplaceAll(name, ".", "")
 		name = strings.ReplaceAll(name, "-", "")
-		if _, found := tracker.PathOf(name); found {
-			// This name collides with some other package
+		if _, found := tracker.PathOf(name); found || name == localLeaf {
+			// This name collides with some other package.
+			// Or, this name is tne same name as the local package,
+			// which we avoid because it can be confusing. For example,
+			// if the local package is v1, we to avoid importing
+			// another package using the v1 name, and instead import
+			// it with a more qualified name, such as metav1.
 			continue
 		}