Remove GridFS chunks if file doc insertion fails.

Fixes #66.

Author: niemeyer

gridfs.go

@@ -521,17 +521,18 @@ func (file *GridFile) completeWrite() {
 		debugf("GridFile %p: waiting for %d pending chunks to complete file write", file, file.wpending)
 		file.c.Wait()
 	}
+	if file.err == nil {
+		hexsum := hex.EncodeToString(file.wsum.Sum(nil))
+		if file.doc.UploadDate.IsZero() {
+			file.doc.UploadDate = bson.Now()
+		}
+		file.doc.MD5 = hexsum
+		file.err = file.gfs.Files.Insert(file.doc)
+		file.gfs.Chunks.EnsureIndexKey("files_id", "n")
+	}
 	if file.err != nil {
 		file.gfs.Chunks.RemoveAll(bson.D{{"files_id", file.doc.Id}})
-		return
-	}
-	hexsum := hex.EncodeToString(file.wsum.Sum(nil))
-	if file.doc.UploadDate.IsZero() {
-		file.doc.UploadDate = bson.Now()
 	}
-	file.doc.MD5 = hexsum
-	file.err = file.gfs.Files.Insert(file.doc)
-	file.gfs.Chunks.EnsureIndexKey("files_id", "n")
 }
 
 // Abort cancels an in-progress write, preventing the file from being

gridfs_test.go

@@ -329,6 +329,34 @@ func (s *S) TestGridFSAbort(c *C) {
 	c.Assert(count, Equals, 0)
 }
 
+func (s *S) TestGridFSCloseConflict(c *C) {
+	session, err := mgo.Dial("localhost:40011")
+	c.Assert(err, IsNil)
+	defer session.Close()
+
+	db := session.DB("mydb")
+
+	db.C("fs.files").EnsureIndex(mgo.Index{Key: []string{"filename"}, Unique: true})
+
+	// For a closing-time conflict
+	err = db.C("fs.files").Insert(M{"filename": "foo.txt"})
+	c.Assert(err, IsNil)
+
+	gfs := db.GridFS("fs")
+	file, err := gfs.Create("foo.txt")
+	c.Assert(err, IsNil)
+
+	_, err = file.Write([]byte("some data"))
+	c.Assert(err, IsNil)
+
+	err = file.Close()
+	c.Assert(mgo.IsDup(err), Equals, true)
+
+	count, err := db.C("fs.chunks").Count()
+	c.Assert(err, IsNil)
+	c.Assert(count, Equals, 0)
+}
+
 func (s *S) TestGridFSOpenNotFound(c *C) {
 	session, err := mgo.Dial("localhost:40011")
 	c.Assert(err, IsNil)