From cebee0b8fa62a31d37bb1a18c5fb9991cfbeaab5 Mon Sep 17 00:00:00 2001
From: Alexander Neumann <alexander@bumpern.de>
Date: Thu, 5 Oct 2017 20:40:02 +0200
Subject: [PATCH] cache: Refuse to cache truncated files

---
 internal/cache/file.go | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/internal/cache/file.go b/internal/cache/file.go
index 33836fc03..5041ad965 100644
--- a/internal/cache/file.go
+++ b/internal/cache/file.go
@@ -111,13 +111,21 @@ func (c *Cache) Save(h restic.Handle, rd io.Reader) error {
 		return err
 	}
 
-	if _, err = io.Copy(f, rd); err != nil {
+	n, err := io.Copy(f, rd)
+	if err != nil {
 		_ = f.Close()
 		_ = c.Remove(h)
 		return errors.Wrap(err, "Copy")
 	}
 
+	if n <= crypto.Extension {
+		_ = f.Close()
+		_ = c.Remove(h)
+		return errors.Errorf("trying to cache truncated file %v", h)
+	}
+
 	if err = f.Close(); err != nil {
+		_ = c.Remove(h)
 		return errors.Wrap(err, "Close")
 	}