Ignore comments in checksum files (#350)

* ignore commented lines when parsing a checksum file

* Update Dockerfile

set noninteractive mode to installation

* Update Dockerfile

pin to go 1.15, because it worked//works there; I suspect this is a "debian changed something" issue.

Dockerfile

@@ -1,9 +1,9 @@
 # Dockerfile to create a go-getter container with smbclient dependency that is used by the get_smb.go tests
-FROM golang:latest
+FROM golang:1.15
 
 COPY . /go-getter
 WORKDIR /go-getter
 
 RUN go mod download
 RUN apt-get update
-RUN apt-get -y install smbclient
+RUN DEBIAN_FRONTEND=noninteractive apt-get -yq install smbclient

checksum.go

@@ -307,6 +307,11 @@ func (c *Client) checksumFromFile(ctx context.Context, checksumURL string, check
 // for BSD type sums parseChecksumLine guesses the hashing algorithm
 // by checking the length of the checksum.
 func parseChecksumLine(line string) (*FileChecksum, error) {
+	switch line[0] {
+	case '#', '/', '-':
+		return nil, nil // skip
+	}
+	//TODO: this function will fail if we pass a checksum for a path with spaces
 	parts := strings.Fields(line)
 
 	switch len(parts) {

get_test.go

@@ -495,6 +495,7 @@ func TestGetFile_checksum_from_file(t *testing.T) {
 		WantTransfer bool
 		WantErr      bool
 	}{
+
 		{
 			"",
 			true,
@@ -548,6 +549,13 @@ func TestGetFile_checksum_from_file(t *testing.T) {
 			true,
 			false,
 		},
+
+		// sha512
+		{
+			"?checksum=file:" + checksums + "/CHECKSUM_sha256_gpg",
+			true,
+			false,
+		},
 	}
 
 	for _, tc := range cases {
@@ -572,6 +580,7 @@ func TestGetFile_checksum_from_file(t *testing.T) {
 				testing_helper.AssertContents(t, dst, "I am a file with some content\n")
 			}
 		})
+		return
 	}
 }
 

testdata/checksum-file/CHECKSUM_sha256_gpg

@@ -0,0 +1,4 @@
+---- something something
+
+# noisey verbose duplicate noise
+SHA256 (content.txt) = 47afcdfff05a6e5d9db5f6c6df2140f04a6e7422d7ad7f6a7006a4f5a78570e4