fix: Nil pointer when getting context's flagSet(#1325) (#1327)

WUST-mengqinyu · web-flow · commit e855c4cd1d5f · 2022-01-16T19:22:57.000-05:00
* fix: Nil pointer when getting context's flagSet in UsageError function(#1325) * test: add unit test for nil flagset in Context
diff --git a/context.go b/context.go
@@ -151,6 +151,9 @@ func (ctx *Context) lookupFlag(name string) Flag {
 
 func (ctx *Context) lookupFlagSet(name string) *flag.FlagSet {
 	for _, c := range ctx.Lineage() {
+		if c.flagSet == nil {
+			continue
+		}
 		if f := c.flagSet.Lookup(name); f != nil {
 			return c.flagSet
 		}
diff --git a/context_test.go b/context_test.go
@@ -112,6 +112,8 @@ func TestContext_String(t *testing.T) {
 	c := NewContext(nil, set, parentCtx)
 	expect(t, c.String("myflag"), "hello world")
 	expect(t, c.String("top-flag"), "hai veld")
+	c = NewContext(nil, nil, parentCtx)
+	expect(t, c.String("top-flag"), "hai veld")
 }
 
 func TestContext_Path(t *testing.T) {

Original file line number	Diff line number	Diff line change
`@@ -151,6 +151,9 @@ func (ctx *Context) lookupFlag(name string) Flag {`
`151`	`151`
`152`	`152`	`func (ctx Context) lookupFlagSet(name string) flag.FlagSet {`
`153`	`153`	`for _, c := range ctx.Lineage() {`
	`154`	`+ if c.flagSet == nil {`
	`155`	`+ continue`
	`156`	`+ }`
`154`	`157`	`if f := c.flagSet.Lookup(name); f != nil {`
`155`	`158`	`return c.flagSet`
`156`	`159`	`}`
Original file line number	Diff line number	Diff line change
`@@ -112,6 +112,8 @@ func TestContext_String(t *testing.T) {`
`112`	`112`	`c := NewContext(nil, set, parentCtx)`
`113`	`113`	`expect(t, c.String("myflag"), "hello world")`
`114`	`114`	`expect(t, c.String("top-flag"), "hai veld")`
	`115`	`+ c = NewContext(nil, nil, parentCtx)`
	`116`	`+ expect(t, c.String("top-flag"), "hai veld")`
`115`	`117`	`}`
`116`	`118`
`117`	`119`	`func TestContext_Path(t *testing.T) {`