Fix ytt formatting issue on colons in multiline strings

pkg/yamlmeta/internal/yaml.v2/emitterc.go

@@ -1002,6 +1002,7 @@ func yamlEmitterAnalyzeScalar(emitter *yamlEmitterT, value []byte) bool {
 		followedByWhitespace = false
 		previousSpace        = false
 		previousBreak        = false
+		previousColon        = false
 	)
 
 	emitter.scalarData.value = value
@@ -1061,7 +1062,11 @@ func yamlEmitterAnalyzeScalar(emitter *yamlEmitterT, value []byte) bool {
 		if !isPrintable(value, i) || !isASCII(value, i) && !emitter.unicode {
 			specialCharacters = true
 		}
-		if isSpace(value, i) {
+		if isColon(value, i) {
+			previousColon = true
+			previousSpace = false
+			previousBreak = false
+		} else if isSpace(value, i) {
 			if i == 0 {
 				leadingSpace = true
 			}
@@ -1081,14 +1086,16 @@ func yamlEmitterAnalyzeScalar(emitter *yamlEmitterT, value []byte) bool {
 			if i+width(value[i]) == len(value) {
 				trailingBreak = true
 			}
-			if previousSpace {
+			if previousSpace && !previousColon {
 				spaceBreak = true
 			}
 			previousSpace = false
 			previousBreak = true
+			previousColon = false
 		} else {
 			previousSpace = false
 			previousBreak = false
+			previousColon = false
 		}
 
 		// [Go]: Why 'z'? Couldn't be the end of the string as that's the loop condition.

pkg/yamlmeta/internal/yaml.v2/encode_test.go

@@ -139,6 +139,18 @@ var marshalTests = []struct {
 		&marshalIntTest,
 		"123\n",
 	},
+	{
+		"a:\n  b",
+		"|-\n  a:\n    b\n",
+	},
+	{
+		"a: \n  b",
+		"|-\n  a: \n    b\n",
+	},
+	{
+		"a:     \n  b",
+		"|-\n  a:     \n    b\n",
+	},
 
 	// Structures
 	{

pkg/yamlmeta/internal/yaml.v2/yamlprivateh.go

@@ -90,6 +90,11 @@ func isSpace(b []byte, i int) bool {
 	return b[i] == ' '
 }
 
+// Check if the character at the specified position is colon.
+func isColon(b []byte, i int) bool {
+	return b[i] == ':'
+}
+
 // Check if the character at the specified position is tab.
 func isTab(b []byte, i int) bool {
 	return b[i] == '\t'