TUN-3922: Repoint urfave/cli/v2 library at patched branch at github.com/ipostelnik/cli/v2@fixed which correctly handles reading flags declared at multiple levels of subcommands.

vendor/github.com/urfave/cli/v2/context.go

@@ -18,6 +18,7 @@ type Context struct {
 	Command       *Command
 	shellComplete bool
 	flagSet       *flag.FlagSet
+	fromFlagSet   map[string]bool
 	parentContext *Context
 }
 
@@ -32,6 +33,14 @@ func NewContext(app *App, set *flag.FlagSet, parentCtx *Context) *Context {
 		}
 	}
 
+	// pre-compute flag seen on the command line at this context
+	c.fromFlagSet = make(map[string]bool)
+	if set != nil {
+		set.Visit(func(f *flag.Flag) {
+			c.fromFlagSet[f.Name] = true
+		})
+	}
+
 	c.Command = &Command{}
 
 	if c.Context == nil {
@@ -48,35 +57,49 @@ func (c *Context) NumFlags() int {
 
 // Set sets a context flag to a value.
 func (c *Context) Set(name, value string) error {
-	return c.flagSet.Set(name, value)
+	err := c.flagSet.Set(name, value)
+	if err == nil {
+		c.fromFlagSet[name] = true
+	}
+
+	return err
 }
 
 // IsSet determines if the flag was actually set
 func (c *Context) IsSet(name string) bool {
-	if fs := lookupFlagSet(name, c); fs != nil {
-		if fs := lookupFlagSet(name, c); fs != nil {
-			isSet := false
-			fs.Visit(func(f *flag.Flag) {
-				if f.Name == name {
-					isSet = true
+	for ctx := c; ctx != nil; ctx = ctx.parentContext {
+		// try flags parsed from command line first
+		if ctx.flagSet.Lookup(name) == nil {
+			// flag not defined in this context
+			continue
+		}
+		if ctx.flagOnCommandLine(name) {
+			return true
+		}
+
+		// now see if value was set externally via environment
+		definedFlags := ctx.Command.Flags
+		if ctx.Command.Name == "" && ctx.App != nil {
+			definedFlags = ctx.App.Flags
+		}
+		for _, ff := range definedFlags {
+			for _, fn := range ff.Names() {
+				if fn == name {
+					if ff.IsSet() {
+						return true
+					}
 				}
-			})
-			if isSet {
-				return true
 			}
 		}
-
-		f := lookupFlag(name, c)
-		if f == nil {
-			return false
-		}
-
-		return f.IsSet()
 	}
 
 	return false
 }
 
+func (c *Context) flagOnCommandLine(name string) bool {
+	return c.fromFlagSet[name]
+}
+
 // LocalFlagNames returns a slice of flag names used in this context.
 func (c *Context) LocalFlagNames() []string {
 	var names []string
@@ -108,7 +131,10 @@ func (c *Context) Lineage() []*Context {
 
 // Value returns the value of the flag corresponding to `name`
 func (c *Context) Value(name string) interface{} {
-	return c.flagSet.Lookup(name).Value.(flag.Getter).Get()
+	if fs := lookupFlagSet(name, c); fs != nil {
+		return fs.Lookup(name).Value.(flag.Getter).Get()
+	}
+	return nil
 }
 
 // Args returns the command line arguments associated with the context.
@@ -150,6 +176,25 @@ func lookupFlag(name string, ctx *Context) Flag {
 	return nil
 }
 
+func (c *Context) resolveFlagDeep(name string) *flag.Flag {
+	var src *flag.Flag
+	for cur := c; cur != nil; cur = cur.parentContext {
+		if f := cur.flagSet.Lookup(name); f != nil {
+			if cur.flagOnCommandLine(name) {
+				// we've found most specific instance on command line, use it
+				src = f
+				break
+			}
+			if src == nil {
+				// flag was defined, but value is not present among flags of the current context
+				// remember the most specific instance of the flag not from command line as fallback
+				src = f
+			}
+		}
+	}
+	return src
+}
+
 func lookupFlagSet(name string, ctx *Context) *flag.FlagSet {
 	for _, c := range ctx.Lineage() {
 		if f := c.flagSet.Lookup(name); f != nil {