Ignore prompt hints

Makes no sense to

Ref: https://gitlab.freedesktop.org/Per_Bothner/specifications/blob/master/proposals/semantic-prompts.md

m/styledStringSplitter.go

@@ -125,7 +125,7 @@ func (s *styledStringSplitter) consumeControlSequence(charAfterEsc rune) bool {
 		if char == ';' || (char >= '0' && char <= '9') {
 			// Sequence still in progress
 
-			if s.input[startIndex:s.nextByteIndex] == "8;;" {
+			if charAfterEsc == ']' && s.input[startIndex:s.nextByteIndex] == "8;;" {
 				// Special case, here comes the URL
 				return s.handleUrl()
 			}
@@ -142,6 +142,10 @@ func (s *styledStringSplitter) consumeControlSequence(charAfterEsc rune) bool {
 // If the whole CSI sequence is ESC[33m, you should call this function with just
 // "33m".
 func (s *styledStringSplitter) handleCompleteControlSequence(charAfterEsc rune, sequence string) bool {
+	if charAfterEsc == ']' {
+		return s.handleOsc(sequence)
+	}
+
 	if charAfterEsc != '[' {
 		return false
 	}
@@ -162,6 +166,24 @@ func (s *styledStringSplitter) handleCompleteControlSequence(charAfterEsc rune,
 	return false
 }
 
+func (s *styledStringSplitter) handleOsc(sequence string) bool {
+	if strings.HasPrefix(sequence, "133;") && len(sequence) == len("133;A") {
+		// Got ESC]133;X, where "X" could be anything. These are prompt hints,
+		// and rendering those makes no sense. We should just ignore them:
+		// https://gitlab.freedesktop.org/Per_Bothner/specifications/blob/master/proposals/semantic-prompts.md
+		endMarker := s.nextChar()
+		if endMarker == '\x07' {
+			return true
+		}
+
+		if endMarker == esc {
+			return s.nextChar() == '\\'
+		}
+	}
+
+	return false
+}
+
 // We just got ESC]8; and should now read the URL. URLs end with ASCII 7 BEL or ESC \.
 func (s *styledStringSplitter) handleUrl() bool {
 	// Valid URL characters.

m/styledStringSplitter_test.go

@@ -3,6 +3,7 @@ package m
 import (
 	"testing"
 
+	"github.com/walles/moar/twin"
 	"gotest.tools/v3/assert"
 )
 
@@ -25,3 +26,23 @@ func TestNextCharLastChar_empty(t *testing.T) {
 	assert.Equal(t, rune(-1), s.nextChar())
 	assert.Equal(t, rune(-1), s.lastChar())
 }
+
+// We should ignore OSC 133 sequences.
+//
+// Ref:
+// https://gitlab.freedesktop.org/Per_Bothner/specifications/blob/master/proposals/semantic-prompts.md
+func TestIgnorePromptHints(t *testing.T) {
+	// From an e-mail I got titled "moar question: "--RAW-CONTROL-CHARS" equivalent"
+	result := styledStringsFromString("\x1b]133;A\x1b\\hello")
+	assert.Equal(t, twin.StyleDefault, result.trailer)
+	assert.Equal(t, 1, len(result.styledStrings))
+	assert.Equal(t, "hello", result.styledStrings[0].String)
+	assert.Equal(t, twin.StyleDefault, result.styledStrings[0].Style)
+
+	// C rather than A, different end-of-sequence, should also be ignored
+	result = styledStringsFromString("\x1b]133;C\x07hello")
+	assert.Equal(t, twin.StyleDefault, result.trailer)
+	assert.Equal(t, 1, len(result.styledStrings))
+	assert.Equal(t, "hello", result.styledStrings[0].String)
+	assert.Equal(t, twin.StyleDefault, result.styledStrings[0].Style)
+}