Fix some issues with unicode handling

There were unicode issues with prompts, search, and syntax highlighting,
which are now fixed.

cmd/micro/highlighter.go

@@ -472,6 +472,7 @@ func Match(v *View) SyntaxMatches {
 					for _, value := range indicies {
 						start := runePos(value[0], line)
 						end := runePos(value[1], line)
+						// messenger.Message(start, " ", end)
 						for i := start; i < end; i++ {
 							matches[lineN][i] = rule.style
 						}

cmd/micro/messenger.go

@@ -249,7 +249,7 @@ func (m *Messenger) HandleEvent(event tcell.Event, history []string) {
 			}
 		case tcell.KeyBackspace2, tcell.KeyBackspace:
 			if m.cursorx > 0 {
-				m.response = string([]rune(m.response)[:m.cursorx-1]) + string(m.response[m.cursorx:])
+				m.response = string([]rune(m.response)[:m.cursorx-1]) + string([]rune(m.response)[m.cursorx:])
 				m.cursorx--
 			}
 		case tcell.KeyRune:

cmd/micro/search.go

@@ -84,10 +84,10 @@ func Search(searchStr string, v *View, down bool) {
 	var charPos int
 	text := v.Buf.String()
 	if down {
-		str = text[searchStart:]
+		str = string([]rune(text)[searchStart:])
 		charPos = searchStart
 	} else {
-		str = text[:searchStart]
+		str = string([]rune(text)[:searchStart])
 	}
 	r, err := regexp.Compile(searchStr)
 	if settings["ignorecase"].(bool) {
@@ -127,7 +127,6 @@ func Search(searchStr string, v *View, down bool) {
 
 	v.Cursor.CurSelection[0] = FromCharPos(charPos+runePos(match[0], str), v.Buf)
 	v.Cursor.CurSelection[1] = FromCharPos(charPos+runePos(match[1], str), v.Buf)
-	v.Cursor.Loc = FromCharPos(charPos+match[1]-1, v.Buf)
 	if v.Relocate() {
 		v.matches = Match(v)
 	}

cmd/micro/view.go

@@ -624,7 +624,8 @@ func (v *View) DisplayView() {
 		}
 
 		// Now we actually draw the line
-		for colN, ch := range line {
+		colN := 0
+		for _, ch := range line {
 			lineStyle := defStyle
 
 			if settings["syntax"].(bool) {
@@ -709,6 +710,7 @@ func (v *View) DisplayView() {
 			}
 			charNum = charNum.Move(1, v.Buf)
 			screenX++
+			colN++
 		}
 		// Here we are at a newline