Fix: (issue#1254) short options handling needs to proceed from last terminated error

Author: dearchap

flag_test.go

@@ -2059,3 +2059,34 @@ func TestTimestampFlagApply_WithDestination(t *testing.T) {
 	expect(t, err, nil)
 	expect(t, *fl.Destination.timestamp, expectedResult)
 }
+
+// Test issue #1254
+// StringSlice() with UseShortOptionHandling causes duplicated entries, depending on the ordering of the flags
+func TestSliceShortOptionHandle(t *testing.T) {
+	_ = (&App{
+		Commands: []*Command{
+			{
+				Name:                   "foobar",
+				UseShortOptionHandling: true,
+				Action: func(ctx *Context) error {
+					if ctx.Bool("i") != true {
+						t.Errorf("bool i not set")
+					}
+					if ctx.Bool("t") != true {
+						t.Errorf("bool i not set")
+					}
+					ss := ctx.StringSlice("net")
+					if !reflect.DeepEqual(ss, []string{"foo"}) {
+						t.Errorf("Got different slice(%v) than expected", ss)
+					}
+					return nil
+				},
+				Flags: []Flag{
+					&StringSliceFlag{Name: "net"},
+					&BoolFlag{Name: "i"},
+					&BoolFlag{Name: "t"},
+				},
+			},
+		},
+	}).Run([]string{"run", "foobar", "--net=foo", "-it"})
+}

parse.go

@@ -46,8 +46,9 @@ func parseIter(set *flag.FlagSet, ip iterativeParser, args []string, shellComple
 				return err
 			}
 
-			// swap current argument with the split version
-			args = append(args[:i], append(shortOpts, args[i+1:]...)...)
+			// Start processing only from failed argument and not
+			// from beginning
+			args = append(shortOpts, args[i+1:]...)
 			argsWereSplit = true
 			break
 		}