Update gopkg.in/yaml.v2 indirect dependency to v2.4.0

vendor/gopkg.in/yaml.v2/decode.go

@@ -4,6 +4,7 @@ import (
 	"encoding"
 	"encoding/base64"
 	"fmt"
+	"io"
 	"math"
 	"reflect"
 	"strconv"
@@ -22,19 +23,22 @@ type node struct {
 	kind         int
 	line, column int
 	tag          string
-	value        string
-	implicit     bool
-	children     []*node
-	anchors      map[string]*node
+	// For an alias node, alias holds the resolved alias.
+	alias    *node
+	value    string
+	implicit bool
+	children []*node
+	anchors  map[string]*node
 }
 
 // ----------------------------------------------------------------------------
 // Parser, produces a node tree out of a libyaml event stream.
 
 type parser struct {
-	parser yaml_parser_t
-	event  yaml_event_t
-	doc    *node
+	parser   yaml_parser_t
+	event    yaml_event_t
+	doc      *node
+	doneInit bool
 }
 
 func newParser(b []byte) *parser {
@@ -42,21 +46,30 @@ func newParser(b []byte) *parser {
 	if !yaml_parser_initialize(&p.parser) {
 		panic("failed to initialize YAML emitter")
 	}
-
 	if len(b) == 0 {
 		b = []byte{'\n'}
 	}
-
 	yaml_parser_set_input_string(&p.parser, b)
-
-	p.skip()
-	if p.event.typ != yaml_STREAM_START_EVENT {
-		panic("expected stream start event, got " + strconv.Itoa(int(p.event.typ)))
-	}
-	p.skip()
 	return &p
 }
 
+func newParserFromReader(r io.Reader) *parser {
+	p := parser{}
+	if !yaml_parser_initialize(&p.parser) {
+		panic("failed to initialize YAML emitter")
+	}
+	yaml_parser_set_input_reader(&p.parser, r)
+	return &p
+}
+
+func (p *parser) init() {
+	if p.doneInit {
+		return
+	}
+	p.expect(yaml_STREAM_START_EVENT)
+	p.doneInit = true
+}
+
 func (p *parser) destroy() {
 	if p.event.typ != yaml_NO_EVENT {
 		yaml_event_delete(&p.event)
@@ -64,16 +77,35 @@ func (p *parser) destroy() {
 	yaml_parser_delete(&p.parser)
 }
 
-func (p *parser) skip() {
-	if p.event.typ != yaml_NO_EVENT {
-		if p.event.typ == yaml_STREAM_END_EVENT {
-			failf("attempted to go past the end of stream; corrupted value?")
+// expect consumes an event from the event stream and
+// checks that it's of the expected type.
+func (p *parser) expect(e yaml_event_type_t) {
+	if p.event.typ == yaml_NO_EVENT {
+		if !yaml_parser_parse(&p.parser, &p.event) {
+			p.fail()
 		}
-		yaml_event_delete(&p.event)
+	}
+	if p.event.typ == yaml_STREAM_END_EVENT {
+		failf("attempted to go past the end of stream; corrupted value?")
+	}
+	if p.event.typ != e {
+		p.parser.problem = fmt.Sprintf("expected %s event but got %s", e, p.event.typ)
+		p.fail()
+	}
+	yaml_event_delete(&p.event)
+	p.event.typ = yaml_NO_EVENT
+}
+
+// peek peeks at the next event in the event stream,
+// puts the results into p.event and returns the event type.
+func (p *parser) peek() yaml_event_type_t {
+	if p.event.typ != yaml_NO_EVENT {
+		return p.event.typ
 	}
 	if !yaml_parser_parse(&p.parser, &p.event) {
 		p.fail()
 	}
+	return p.event.typ
 }
 
 func (p *parser) fail() {
@@ -81,6 +113,10 @@ func (p *parser) fail() {
 	var line int
 	if p.parser.problem_mark.line != 0 {
 		line = p.parser.problem_mark.line
+		// Scanner errors don't iterate line before returning error
+		if p.parser.error == yaml_SCANNER_ERROR {
+			line++
+		}
 	} else if p.parser.context_mark.line != 0 {
 		line = p.parser.context_mark.line
 	}
@@ -103,7 +139,8 @@ func (p *parser) anchor(n *node, anchor []byte) {
 }
 
 func (p *parser) parse() *node {
-	switch p.event.typ {
+	p.init()
+	switch p.peek() {
 	case yaml_SCALAR_EVENT:
 		return p.scalar()
 	case yaml_ALIAS_EVENT:
@@ -118,7 +155,7 @@ func (p *parser) parse() *node {
 		// Happens when attempting to decode an empty buffer.
 		return nil
 	default:
-		panic("attempted to parse unknown event: " + strconv.Itoa(int(p.event.typ)))
+		panic("attempted to parse unknown event: " + p.event.typ.String())
 	}
 }
 
@@ -134,19 +171,20 @@ func (p *parser) document() *node {
 	n := p.node(documentNode)
 	n.anchors = make(map[string]*node)
 	p.doc = n
-	p.skip()
+	p.expect(yaml_DOCUMENT_START_EVENT)
 	n.children = append(n.children, p.parse())
-	if p.event.typ != yaml_DOCUMENT_END_EVENT {
-		panic("expected end of document event but got " + strconv.Itoa(int(p.event.typ)))
-	}
-	p.skip()
+	p.expect(yaml_DOCUMENT_END_EVENT)
 	return n
 }
 
 func (p *parser) alias() *node {
 	n := p.node(aliasNode)
 	n.value = string(p.event.anchor)
-	p.skip()
+	n.alias = p.doc.anchors[n.value]
+	if n.alias == nil {
+		failf("unknown anchor '%s' referenced", n.value)
+	}
+	p.expect(yaml_ALIAS_EVENT)
 	return n
 }
 
@@ -156,29 +194,29 @@ func (p *parser) scalar() *node {
 	n.tag = string(p.event.tag)
 	n.implicit = p.event.implicit
 	p.anchor(n, p.event.anchor)
-	p.skip()
+	p.expect(yaml_SCALAR_EVENT)
 	return n
 }
 
 func (p *parser) sequence() *node {
 	n := p.node(sequenceNode)
 	p.anchor(n, p.event.anchor)
-	p.skip()
-	for p.event.typ != yaml_SEQUENCE_END_EVENT {
+	p.expect(yaml_SEQUENCE_START_EVENT)
+	for p.peek() != yaml_SEQUENCE_END_EVENT {
 		n.children = append(n.children, p.parse())
 	}
-	p.skip()
+	p.expect(yaml_SEQUENCE_END_EVENT)
 	return n
 }
 
 func (p *parser) mapping() *node {
 	n := p.node(mappingNode)
 	p.anchor(n, p.event.anchor)
-	p.skip()
-	for p.event.typ != yaml_MAPPING_END_EVENT {
+	p.expect(yaml_MAPPING_START_EVENT)
+	for p.peek() != yaml_MAPPING_END_EVENT {
 		n.children = append(n.children, p.parse(), p.parse())
 	}
-	p.skip()
+	p.expect(yaml_MAPPING_END_EVENT)
 	return n
 }
 
@@ -187,10 +225,14 @@ func (p *parser) mapping() *node {
 
 type decoder struct {
 	doc     *node
-	aliases map[string]bool
+	aliases map[*node]bool
 	mapType reflect.Type
 	terrors []string
 	strict  bool
+
+	decodeCount int
+	aliasCount  int
+	aliasDepth  int
 }
 
 var (
@@ -198,11 +240,13 @@ var (
 	durationType   = reflect.TypeOf(time.Duration(0))
 	defaultMapType = reflect.TypeOf(map[interface{}]interface{}{})
 	ifaceType      = defaultMapType.Elem()
+	timeType       = reflect.TypeOf(time.Time{})
+	ptrTimeType    = reflect.TypeOf(&time.Time{})
 )
 
 func newDecoder(strict bool) *decoder {
 	d := &decoder{mapType: defaultMapType, strict: strict}
-	d.aliases = make(map[string]bool)
+	d.aliases = make(map[*node]bool)
 	return d
 }
 
@@ -251,7 +295,7 @@ func (d *decoder) callUnmarshaler(n *node, u Unmarshaler) (good bool) {
 //
 // If n holds a null value, prepare returns before doing anything.
 func (d *decoder) prepare(n *node, out reflect.Value) (newout reflect.Value, unmarshaled, good bool) {
-	if n.tag == yaml_NULL_TAG || n.kind == scalarNode && n.tag == "" && (n.value == "null" || n.value == "" && n.implicit) {
+	if n.tag == yaml_NULL_TAG || n.kind == scalarNode && n.tag == "" && (n.value == "null" || n.value == "~" || n.value == "" && n.implicit) {
 		return out, false, false
 	}
 	again := true
@@ -274,7 +318,43 @@ func (d *decoder) prepare(n *node, out reflect.Value) (newout reflect.Value, unm
 	return out, false, false
 }
 
+const (
+	// 400,000 decode operations is ~500kb of dense object declarations, or
+	// ~5kb of dense object declarations with 10000% alias expansion
+	alias_ratio_range_low = 400000
+
+	// 4,000,000 decode operations is ~5MB of dense object declarations, or
+	// ~4.5MB of dense object declarations with 10% alias expansion
+	alias_ratio_range_high = 4000000
+
+	// alias_ratio_range is the range over which we scale allowed alias ratios
+	alias_ratio_range = float64(alias_ratio_range_high - alias_ratio_range_low)
+)
+
+func allowedAliasRatio(decodeCount int) float64 {
+	switch {
+	case decodeCount <= alias_ratio_range_low:
+		// allow 99% to come from alias expansion for small-to-medium documents
+		return 0.99
+	case decodeCount >= alias_ratio_range_high:
+		// allow 10% to come from alias expansion for very large documents
+		return 0.10
+	default:
+		// scale smoothly from 99% down to 10% over the range.
+		// this maps to 396,000 - 400,000 allowed alias-driven decodes over the range.
+		// 400,000 decode operations is ~100MB of allocations in worst-case scenarios (single-item maps).
+		return 0.99 - 0.89*(float64(decodeCount-alias_ratio_range_low)/alias_ratio_range)
+	}
+}
+
 func (d *decoder) unmarshal(n *node, out reflect.Value) (good bool) {
+	d.decodeCount++
+	if d.aliasDepth > 0 {
+		d.aliasCount++
+	}
+	if d.aliasCount > 100 && d.decodeCount > 1000 && float64(d.aliasCount)/float64(d.decodeCount) > allowedAliasRatio(d.decodeCount) {
+		failf("document contains excessive aliasing")
+	}
 	switch n.kind {
 	case documentNode:
 		return d.document(n, out)
@@ -308,16 +388,15 @@ func (d *decoder) document(n *node, out reflect.Value) (good bool) {
 }
 
 func (d *decoder) alias(n *node, out reflect.Value) (good bool) {
-	an, ok := d.doc.anchors[n.value]
-	if !ok {
-		failf("unknown anchor '%s' referenced", n.value)
-	}
-	if d.aliases[n.value] {
+	if d.aliases[n] {
+		// TODO this could actually be allowed in some circumstances.
 		failf("anchor '%s' value contains itself", n.value)
 	}
-	d.aliases[n.value] = true
-	good = d.unmarshal(an, out)
-	delete(d.aliases, n.value)
+	d.aliases[n] = true
+	d.aliasDepth++
+	good = d.unmarshal(n.alias, out)
+	d.aliasDepth--
+	delete(d.aliases, n)
 	return good
 }
 
@@ -329,7 +408,7 @@ func resetMap(out reflect.Value) {
 	}
 }
 
-func (d *decoder) scalar(n *node, out reflect.Value) (good bool) {
+func (d *decoder) scalar(n *node, out reflect.Value) bool {
 	var tag string
 	var resolved interface{}
 	if n.tag == "" && !n.implicit {
@@ -353,9 +432,26 @@ func (d *decoder) scalar(n *node, out reflect.Value) (good bool) {
 		}
 		return true
 	}
-	if s, ok := resolved.(string); ok && out.CanAddr() {
-		if u, ok := out.Addr().Interface().(encoding.TextUnmarshaler); ok {
-			err := u.UnmarshalText([]byte(s))
+	if resolvedv := reflect.ValueOf(resolved); out.Type() == resolvedv.Type() {
+		// We've resolved to exactly the type we want, so use that.
+		out.Set(resolvedv)
+		return true
+	}
+	// Perhaps we can use the value as a TextUnmarshaler to
+	// set its value.
+	if out.CanAddr() {
+		u, ok := out.Addr().Interface().(encoding.TextUnmarshaler)
+		if ok {
+			var text []byte
+			if tag == yaml_BINARY_TAG {
+				text = []byte(resolved.(string))
+			} else {
+				// We let any value be unmarshaled into TextUnmarshaler.
+				// That might be more lax than we'd like, but the
+				// TextUnmarshaler itself should bowl out any dubious values.
+				text = []byte(n.value)
+			}
+			err := u.UnmarshalText(text)
 			if err != nil {
 				fail(err)
 			}
@@ -366,46 +462,54 @@ func (d *decoder) scalar(n *node, out reflect.Value) (good bool) {
 	case reflect.String:
 		if tag == yaml_BINARY_TAG {
 			out.SetString(resolved.(string))
-			good = true
-		} else if resolved != nil {
+			return true
+		}
+		if resolved != nil {
 			out.SetString(n.value)
-			good = true
+			return true
 		}
 	case reflect.Interface:
 		if resolved == nil {
 			out.Set(reflect.Zero(out.Type()))
+		} else if tag == yaml_TIMESTAMP_TAG {
+			// It looks like a timestamp but for backward compatibility
+			// reasons we set it as a string, so that code that unmarshals
+			// timestamp-like values into interface{} will continue to
+			// see a string and not a time.Time.
+			// TODO(v3) Drop this.
+			out.Set(reflect.ValueOf(n.value))
 		} else {
 			out.Set(reflect.ValueOf(resolved))
 		}
-		good = true
+		return true
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
 		switch resolved := resolved.(type) {
 		case int:
 			if !out.OverflowInt(int64(resolved)) {
 				out.SetInt(int64(resolved))
-				good = true
+				return true
 			}
 		case int64:
 			if !out.OverflowInt(resolved) {
 				out.SetInt(resolved)
-				good = true
+				return true
 			}
 		case uint64:
 			if resolved <= math.MaxInt64 && !out.OverflowInt(int64(resolved)) {
 				out.SetInt(int64(resolved))
-				good = true
+				return true
 			}
 		case float64:
 			if resolved <= math.MaxInt64 && !out.OverflowInt(int64(resolved)) {
 				out.SetInt(int64(resolved))
-				good = true
+				return true
 			}
 		case string:
 			if out.Type() == durationType {
 				d, err := time.ParseDuration(resolved)
 				if err == nil {
 					out.SetInt(int64(d))
-					good = true
+					return true
 				}
 			}
 		}
@@ -414,44 +518,49 @@ func (d *decoder) scalar(n *node, out reflect.Value) (good bool) {
 		case int:
 			if resolved >= 0 && !out.OverflowUint(uint64(resolved)) {
 				out.SetUint(uint64(resolved))
-				good = true
+				return true
 			}
 		case int64:
 			if resolved >= 0 && !out.OverflowUint(uint64(resolved)) {
 				out.SetUint(uint64(resolved))
-				good = true
+				return true
 			}
 		case uint64:
 			if !out.OverflowUint(uint64(resolved)) {
 				out.SetUint(uint64(resolved))
-				good = true
+				return true
 			}
 		case float64:
 			if resolved <= math.MaxUint64 && !out.OverflowUint(uint64(resolved)) {
 				out.SetUint(uint64(resolved))
-				good = true
+				return true
 			}
 		}
 	case reflect.Bool:
 		switch resolved := resolved.(type) {
 		case bool:
 			out.SetBool(resolved)
-			good = true
+			return true
 		}
 	case reflect.Float32, reflect.Float64:
 		switch resolved := resolved.(type) {
 		case int:
 			out.SetFloat(float64(resolved))
-			good = true
+			return true
 		case int64:
 			out.SetFloat(float64(resolved))
-			good = true
+			return true
 		case uint64:
 			out.SetFloat(float64(resolved))
-			good = true
+			return true
 		case float64:
 			out.SetFloat(resolved)
-			good = true
+			return true
+		}
+	case reflect.Struct:
+		if resolvedv := reflect.ValueOf(resolved); out.Type() == resolvedv.Type() {
+			out.Set(resolvedv)
+			return true
 		}
 	case reflect.Ptr:
 		if out.Type().Elem() == reflect.TypeOf(resolved) {
@@ -459,13 +568,11 @@ func (d *decoder) scalar(n *node, out reflect.Value) (good bool) {
 			elem := reflect.New(out.Type().Elem())
 			elem.Elem().Set(reflect.ValueOf(resolved))
 			out.Set(elem)
-			good = true
+			return true
 		}
 	}
-	if !good {
-		d.terror(n, tag, out)
-	}
-	return good
+	d.terror(n, tag, out)
+	return false
 }
 
 func settableValueOf(i interface{}) reflect.Value {
@@ -482,6 +589,10 @@ func (d *decoder) sequence(n *node, out reflect.Value) (good bool) {
 	switch out.Kind() {
 	case reflect.Slice:
 		out.Set(reflect.MakeSlice(out.Type(), l, l))
+	case reflect.Array:
+		if l != out.Len() {
+			failf("invalid array: want %d elements but got %d", out.Len(), l)
+		}
 	case reflect.Interface:
 		// No type hints. Will have to use a generic sequence.
 		iface = out
@@ -500,7 +611,9 @@ func (d *decoder) sequence(n *node, out reflect.Value) (good bool) {
 			j++
 		}
 	}
-	out.Set(out.Slice(0, j))
+	if out.Kind() != reflect.Array {
+		out.Set(out.Slice(0, j))
+	}
 	if iface.IsValid() {
 		iface.Set(out)
 	}
@@ -561,7 +674,7 @@ func (d *decoder) mapping(n *node, out reflect.Value) (good bool) {
 			}
 			e := reflect.New(et).Elem()
 			if d.unmarshal(n.children[i+1], e) {
-				out.SetMapIndex(k, e)
+				d.setMapIndex(n.children[i+1], out, k, e)
 			}
 		}
 	}
@@ -569,6 +682,14 @@ func (d *decoder) mapping(n *node, out reflect.Value) (good bool) {
 	return true
 }
 
+func (d *decoder) setMapIndex(n *node, out, k, v reflect.Value) {
+	if d.strict && out.MapIndex(k) != zeroValue {
+		d.terrors = append(d.terrors, fmt.Sprintf("line %d: key %#v already set in map", n.line+1, k.Interface()))
+		return
+	}
+	out.SetMapIndex(k, v)
+}
+
 func (d *decoder) mappingSlice(n *node, out reflect.Value) (good bool) {
 	outt := out.Type()
 	if outt.Elem() != mapItemType {
@@ -616,6 +737,10 @@ func (d *decoder) mappingStruct(n *node, out reflect.Value) (good bool) {
 		elemType = inlineMap.Type().Elem()
 	}
 
+	var doneFields []bool
+	if d.strict {
+		doneFields = make([]bool, len(sinfo.FieldsList))
+	}
 	for i := 0; i < l; i += 2 {
 		ni := n.children[i]
 		if isMerge(ni) {
@@ -626,6 +751,13 @@ func (d *decoder) mappingStruct(n *node, out reflect.Value) (good bool) {
 			continue
 		}
 		if info, ok := sinfo.FieldsMap[name.String()]; ok {
+			if d.strict {
+				if doneFields[info.Id] {
+					d.terrors = append(d.terrors, fmt.Sprintf("line %d: field %s already set in type %s", ni.line+1, name.String(), out.Type()))
+					continue
+				}
+				doneFields[info.Id] = true
+			}
 			var field reflect.Value
 			if info.Inline == nil {
 				field = out.Field(info.Num)
@@ -639,9 +771,9 @@ func (d *decoder) mappingStruct(n *node, out reflect.Value) (good bool) {
 			}
 			value := reflect.New(elemType).Elem()
 			d.unmarshal(n.children[i+1], value)
-			inlineMap.SetMapIndex(name, value)
+			d.setMapIndex(n.children[i+1], inlineMap, name, value)
 		} else if d.strict {
-			d.terrors = append(d.terrors, fmt.Sprintf("line %d: field %s not found in struct %s", n.line+1, name.String(), out.Type()))
+			d.terrors = append(d.terrors, fmt.Sprintf("line %d: field %s not found in type %s", ni.line+1, name.String(), out.Type()))
 		}
 	}
 	return true
@@ -656,8 +788,7 @@ func (d *decoder) merge(n *node, out reflect.Value) {
 	case mappingNode:
 		d.unmarshal(n, out)
 	case aliasNode:
-		an, ok := d.doc.anchors[n.value]
-		if ok && an.kind != mappingNode {
+		if n.alias != nil && n.alias.kind != mappingNode {
 			failWantMap()
 		}
 		d.unmarshal(n, out)
@@ -666,8 +797,7 @@ func (d *decoder) merge(n *node, out reflect.Value) {
 		for i := len(n.children) - 1; i >= 0; i-- {
 			ni := n.children[i]
 			if ni.kind == aliasNode {
-				an, ok := d.doc.anchors[ni.value]
-				if ok && an.kind != mappingNode {
+				if ni.alias != nil && ni.alias.kind != mappingNode {
 					failWantMap()
 				}
 			} else if ni.kind != mappingNode {