code review 5712045: path/filepath: steer people away from HasPrefix

src/pkg/path/filepath/path_plan9.go

Index: src/pkg/path/filepath/path_plan9.go
===================================================================
--- a/src/pkg/path/filepath/path_plan9.go
+++ b/src/pkg/path/filepath/path_plan9.go
@@ -17,7 +17,7 @@
 	return ""
 }
 
-// HasPrefix tests whether the path p begins with prefix.
+// HasPrefix exists for historical compatibility and should not be used.
 func HasPrefix(p, prefix string) bool {
 	return strings.HasPrefix(p, prefix)
 }