fix #3897

bug fix for file-provisioner download file, including unit-test code.

provisioner/file/provisioner.go

@@ -109,7 +109,7 @@ func (p *Provisioner) ProvisionDownload(ui packer.Ui, comm packer.Communicator)
 			}
 		}
 		// if the config.Destination was a dir, download the dir
-		if !strings.HasSuffix(p.config.Destination, "/") {
+		if strings.HasSuffix(p.config.Destination, "/") {
 			return comm.DownloadDir(src, p.config.Destination, nil)
 		}
 

provisioner/file/provisioner_test.go

@@ -192,5 +192,9 @@ func TestProvisionDownloadMkdirAll(t *testing.T) {
 		if _, err := os.Stat(path); err != nil {
 			t.Fatalf("stat of download dir should not error: %s", err)
 		}
+
+		if _, err := os.Stat(config["destination"].(string)); err != nil {
+			t.Fatalf("stat of destination file should not error: %s", err)
+		}
 	}
 }