review and undo headings wrap past the label column; format characters take a column

1 files changed, 6 insertions, 3 deletions

diff --git a/cmd/krino/render.go b/cmd/krino/render.go
index 7205488..5b75df3 100644
--- a/cmd/krino/render.go
+++ b/cmd/krino/render.go
@@ -325,8 +325,11 @@ func wrapText(s string, max int) []string {
 }
 
 // cols is how many terminal columns s takes: two for a wide or full-width
-// character (CJK), none for a combining mark or format character, one for
-// the rest (triage 28j).
+// character (CJK), none for a combining mark, one for the rest - format
+// characters included: a terminal may draw one (a soft hyphen), and
+// counting a column too many only wraps early, while one too few runs past
+// the edge (triage 28j, plan 11 review L4). A terminal can still draw some
+// characters wider (emoji, ambiguous-width letters); see KNOWN LIMITATIONS.
 func cols(s string) int {
 	n := 0
 	for _, r := range s {
@@ -336,7 +339,7 @@ func cols(s string) int {
 }
 
 func runeCols(r rune) int {
-	if unicode.In(r, unicode.Mn, unicode.Me, unicode.Cf) {
+	if unicode.In(r, unicode.Mn, unicode.Me) {
 		return 0
 	}
 	switch width.LookupRune(r).Kind() {