resources/images: Make the image cache more robust

Also allow timeout to be set as a duration string, e.g. `30s`.

Fixes #6501

2 files changed, 3 insertions, 3 deletions

diff --git a/cache/filecache/filecache.go b/cache/filecache/filecache.go
index 3628300fb..37870dd5f 100644
--- a/cache/filecache/filecache.go
+++ b/cache/filecache/filecache.go
@@ -129,7 +129,7 @@ func (c *Cache) WriteCloser(id string) (ItemInfo, io.WriteCloser, error) {
 // If not found a new file is created and passed to create, which should close
 // it when done.
 func (c *Cache) ReadOrCreate(id string,
-	read func(info ItemInfo, r io.Reader) error,
+	read func(info ItemInfo, r io.ReadSeeker) error,
 	create func(info ItemInfo, w io.WriteCloser) error) (info ItemInfo, err error) {
 	id = cleanID(id)
 
diff --git a/cache/filecache/filecache_test.go b/cache/filecache/filecache_test.go
index a4bf45fe0..5a5dac983 100644
--- a/cache/filecache/filecache_test.go
+++ b/cache/filecache/filecache_test.go
@@ -250,9 +250,9 @@ func TestFileCacheReadOrCreateErrorInRead(t *testing.T) {
 
 	var result string
 
-	rf := func(failLevel int) func(info ItemInfo, r io.Reader) error {
+	rf := func(failLevel int) func(info ItemInfo, r io.ReadSeeker) error {
 
-		return func(info ItemInfo, r io.Reader) error {
+		return func(info ItemInfo, r io.ReadSeeker) error {
 			if failLevel > 0 {
 				if failLevel > 1 {
 					return ErrFatal