internal/flags: fix issue with stringslice migration

internal/flags/helpers.go

@@ -92,10 +92,34 @@ func MigrateGlobalFlags(ctx *cli.Context) {
 }
 
 func doMigrateFlags(ctx *cli.Context) {
+ // Figure out if there are any aliases of commands. If there are, we want
+ // to ignore them when iterating over the flags.
+ var aliases = make(map[string]bool)
+ for _, fl := range ctx.Command.Flags {
+ for _, alias := range fl.Names()[1:] {
+ aliases[alias] = true
+ }
+ }
  for _, name := range ctx.FlagNames() {
  for _, parent := range ctx.Lineage()[1:] {
  if parent.IsSet(name) {
- ctx.Set(name, parent.String(name))
+ // When iterating across the lineage, we will be served both
+ // the 'canon' and alias formats of all commmands. In most cases,
+ // it's fine to set it in the ctx multiple times (one for each
+ // name), however, the Slice-flags are not fine.
+ // The slice-flags accumulate, so if we set it once as
+ // "foo" and once as alias "F", then both will be present in the slice.
+ if _, isAlias := aliases[name]; isAlias {
+ continue
+ }
+ // If it is a string-slice, we need to set it as
+ // "alfa, beta, gamma" instead of "[alfa beta gamma]", in order
+ // for the backing StringSlice to parse it properly.
+ if result := parent.StringSlice(name); len(result) > 0 {
+ ctx.Set(name, strings.Join(result, ","))
+ } else {
+ ctx.Set(name, parent.String(name))
+ }
  break
  }
  }