zfs: dry send: handle spaces in dataset names correctly

fixes #131

zfs/zfs.go

@@ -577,10 +577,17 @@ type DrySendInfo struct {
 	SizeEstimate int64 // -1 if size estimate is not possible
 }
 
-var sendDryRunInfoLineRegex = regexp.MustCompile(`^(full|incremental)(\t(\S+))?\t(\S+)\t([0-9]+)$`)
+var (
+	// keep same number of capture groups for unmarshalInfoLine homogenity
+
+	sendDryRunInfoLineRegexFull = regexp.MustCompile(`^(full)\t()([^\t]+@[^\t]+)\t([0-9]+)$`)
+	// cannot enforce '[#@]' in incremental source, see test cases  
+	sendDryRunInfoLineRegexIncremental = regexp.MustCompile(`^(incremental)\t([^\t]+)\t([^\t]+@[^\t]+)\t([0-9]+)$`)
+)
 
 // see test cases for example output
 func (s *DrySendInfo) unmarshalZFSOutput(output []byte) (err error) {
+	debug("DrySendInfo.unmarshalZFSOutput: output=%q", output)
 	lines := strings.Split(string(output), "\n")
 	for _, l := range lines {
 		regexMatched, err := s.unmarshalInfoLine(l)
@@ -592,7 +599,7 @@ func (s *DrySendInfo) unmarshalZFSOutput(output []byte) (err error) {
 		}
 		return nil
 	}
-	return fmt.Errorf("no match for info line (regex %s)", sendDryRunInfoLineRegex)
+	return fmt.Errorf("no match for info line (regex1 %s) (regex2 %s)", sendDryRunInfoLineRegexFull, sendDryRunInfoLineRegexIncremental)
 }
 
 
@@ -602,24 +609,32 @@ func (s *DrySendInfo) unmarshalZFSOutput(output []byte) (err error) {
 // => see test cases
 func (s *DrySendInfo) unmarshalInfoLine(l string) (regexMatched bool, err error) {
 
-	m := sendDryRunInfoLineRegex.FindStringSubmatch(l)
+	mFull := sendDryRunInfoLineRegexFull.FindStringSubmatch(l)
-	if m == nil {
+	mInc := sendDryRunInfoLineRegexIncremental.FindStringSubmatch(l)
+	var m []string
+	if mFull == nil && mInc == nil {
 		return false, nil
+	} else if mFull != nil && mInc != nil {
+		panic(fmt.Sprintf("ambiguous ZFS dry send output: %q", l))
+	} else if mFull != nil {
+		m = mFull
+	} else if mInc != nil {
+		m = mInc
 	}
 	s.Type, err = DrySendTypeFromString(m[1])
 	if err != nil {
 		return true, err
 	}
 
-	s.From = m[3]
+	s.From = m[2]
-	s.To = m[4]
+	s.To = m[3]
-	toFS, _, _ , err := DecomposeVersionString(s.To)
+	toFS, _, _, err := DecomposeVersionString(s.To)
 	if err != nil {
 		return true, fmt.Errorf("'to' is not a valid filesystem version: %s", err)
 	}
 	s.Filesystem = toFS
 
-	s.SizeEstimate, err = strconv.ParseInt(m[5], 10, 64)
+	s.SizeEstimate, err = strconv.ParseInt(m[4], 10, 64)
 	if err != nil {
 		return true, fmt.Errorf("cannot not parse size: %s", err)
 	}

zfs/zfs_test.go

@@ -70,6 +70,10 @@ func TestZFSPropertySource(t *testing.T) {
 
 }
 
+func TestDrySendRegexesHaveSameCaptureGroupCount(t *testing.T) {
+	assert.Equal(t, sendDryRunInfoLineRegexFull.NumSubexp(), sendDryRunInfoLineRegexIncremental.NumSubexp())
+}
+
 func TestDrySendInfo(t *testing.T) {
 
 	// # full send
@@ -127,6 +131,11 @@ full	zroot/test/a@3	10518512
 size	10518512
 `
 
+	fullWithSpaces := "\nfull\tpool1/otherjob/ds with spaces@blaffoo\t12912\nsize\t12912\n"
+	fullWithSpacesInIntermediateComponent := "\nfull\tpool1/otherjob/another ds with spaces/childfs@blaffoo\t12912\nsize\t12912\n"
+	incrementalWithSpaces := "\nincremental\tblaffoo\tpool1/otherjob/another ds with spaces@blaffoo2\t624\nsize\t624\n"
+	incrementalWithSpacesInIntermediateComponent := "\nincremental\tblaffoo\tpool1/otherjob/another ds with spaces/childfs@blaffoo2\t624\nsize\t624\n"
+
 	type tc struct {
 		name string
 		in string
@@ -187,6 +196,46 @@ size	10518512
 				SizeEstimate: 10518512,
 			},
 		},
+		{
+			name: "fullWithSpaces", in: fullWithSpaces,
+			exp: &DrySendInfo{
+				Type:         DrySendTypeFull,
+				Filesystem:   "pool1/otherjob/ds with spaces",
+				From:         "",
+				To:           "pool1/otherjob/ds with spaces@blaffoo",
+				SizeEstimate: 12912,
+			},
+		},
+		{
+			name: "fullWithSpacesInIntermediateComponent", in: fullWithSpacesInIntermediateComponent,
+			exp: &DrySendInfo{
+				Type:         DrySendTypeFull,
+				Filesystem:   "pool1/otherjob/another ds with spaces/childfs",
+				From:         "",
+				To:           "pool1/otherjob/another ds with spaces/childfs@blaffoo",
+				SizeEstimate: 12912,
+			},
+		},
+		{
+			name: "incrementalWithSpaces", in: incrementalWithSpaces,
+			exp: &DrySendInfo{
+				Type:         DrySendTypeIncremental,
+				Filesystem:   "pool1/otherjob/another ds with spaces",
+				From:         "blaffoo",
+				To:           "pool1/otherjob/another ds with spaces@blaffoo2",
+				SizeEstimate: 624,
+			},
+		},
+		{
+			name: "incrementalWithSpacesInIntermediateComponent", in: incrementalWithSpacesInIntermediateComponent,
+			exp: &DrySendInfo{
+				Type:         DrySendTypeIncremental,
+				Filesystem:   "pool1/otherjob/another ds with spaces/childfs",
+				From:         "blaffoo",
+				To:           "pool1/otherjob/another ds with spaces/childfs@blaffoo2",
+				SizeEstimate: 624,
+			},
+		},
 	}
 
 	for _, tc := range tcs {