Merge pull request #40784 from thaJeztah/19.03_update_buildkit

[19.03] vendor buildkit b26cff2413cc6a466f8739262efa13bd126f8fc7

vendor.conf

@@ -26,7 +26,7 @@ github.com/imdario/mergo                            7c29201646fa3de8506f70121347
 golang.org/x/sync                                   e225da77a7e68af35c70ccbf71af2b83e6acac3c
 
 # buildkit
-github.com/moby/buildkit                            ebcef1f69af0bbca077efa9a960a481e579a0e89 # v0.6.4
+github.com/moby/buildkit                            b26cff2413cc6a466f8739262efa13bd126f8fc7 # v0.6.4 + aa7df97d7136e732561b59f87a38ad52d46d3b19
 github.com/tonistiigi/fsutil                        6c909ab392c173a4264ae1bfcbc0450b9aac0c7d
 github.com/grpc-ecosystem/grpc-opentracing          8e809c8a86450a29b90dcc9efbf062d0fe6d9746
 github.com/opentracing/opentracing-go               1361b9cd60be79c4c3a7fa9841b3c132e40066a7

vendor/github.com/moby/buildkit/solver/cachemanager.go

@@ -150,8 +150,12 @@ type LoadedResult struct {
 	CacheKey    *CacheKey
 }
 
-func (c *cacheManager) filterResults(m map[string]Result, ck *CacheKey) (results []LoadedResult, err error) {
+func (c *cacheManager) filterResults(m map[string]Result, ck *CacheKey, visited map[string]struct{}) (results []LoadedResult, err error) {
 	id := c.getID(ck)
+	if _, ok := visited[id]; ok {
+		return nil, nil
+	}
+	visited[id] = struct{}{}
 	if err := c.backend.WalkResults(id, func(cr CacheResult) error {
 		res, ok := m[id]
 		if ok {
@@ -170,7 +174,7 @@ func (c *cacheManager) filterResults(m map[string]Result, ck *CacheKey) (results
 	}
 	for _, keys := range ck.Deps() {
 		for _, key := range keys {
-			res, err := c.filterResults(m, key.CacheKey.CacheKey)
+			res, err := c.filterResults(m, key.CacheKey.CacheKey, visited)
 			if err != nil {
 				for _, r := range results {
 					r.Result.Release(context.TODO())
@@ -207,7 +211,7 @@ func (c *cacheManager) LoadWithParents(ctx context.Context, rec *CacheRecord) ([
 		return nil, err
 	}
 
-	results, err := c.filterResults(m, rec.key)
+	results, err := c.filterResults(m, rec.key, map[string]struct{}{})
 	if err != nil {
 		for _, r := range m {
 			r.Release(context.TODO())