Implement word wrapping in the list section

src/util/chars.go

@@ -249,7 +249,7 @@ func (chars *Chars) Prepend(prefix string) {
 	}
 }
 
-func (chars *Chars) Lines(multiLine bool, maxLines int, wrapCols int, wrapSignWidth int, tabstop int) ([][]rune, bool) {
+func (chars *Chars) Lines(multiLine bool, maxLines int, wrapCols int, wrapSignWidth int, tabstop int, wrapWord bool) ([][]rune, bool) {
 	text := make([]rune, chars.Length())
 	copy(text, chars.ToRunes())
 
@@ -307,6 +307,19 @@ func (chars *Chars) Lines(multiLine bool, maxLines int, wrapCols int, wrapSignWi
 				if overflowIdx == 0 {
 					overflowIdx = 1
 				}
+				if wrapWord {
+					// Find last space/tab at or before overflowIdx
+					breakIdx := -1
+					for k := overflowIdx; k > 0; k-- {
+						if line[k-1] == ' ' || line[k-1] == '\t' {
+							breakIdx = k
+							break
+						}
+					}
+					if breakIdx > 0 {
+						overflowIdx = breakIdx
+					}
+				}
 				if len(wrapped) >= maxLines {
 					return wrapped, true
 				}

src/util/chars_test.go

@@ -51,7 +51,7 @@ func TestTrimLength(t *testing.T) {
 func TestCharsLines(t *testing.T) {
 	chars := ToChars([]byte("abcdef\n가나다\n\tdef"))
 	check := func(multiLine bool, maxLines int, wrapCols int, wrapSignWidth int, tabstop int, expectedNumLines int, expectedOverflow bool) {
-		lines, overflow := chars.Lines(multiLine, maxLines, wrapCols, wrapSignWidth, tabstop)
+		lines, overflow := chars.Lines(multiLine, maxLines, wrapCols, wrapSignWidth, tabstop, false)
 		fmt.Println(lines, overflow)
 		if len(lines) != expectedNumLines || overflow != expectedOverflow {
 			t.Errorf("Invalid result: %d %v (expected %d %v)", len(lines), overflow, expectedNumLines, expectedOverflow)
@@ -81,3 +81,51 @@ func TestCharsLines(t *testing.T) {
 	// With wrap sign (3 + 2) and no multi-line
 	check(false, 100, 3, 2, 1, 13, false)
 }
+
+func TestCharsLinesWrapWord(t *testing.T) {
+	// "hello world foo bar" with width 12 should break at word boundaries
+	chars := ToChars([]byte("hello world foo bar"))
+	lines, overflow := chars.Lines(false, 100, 12, 0, 8, true)
+	// "hello world " (12) | "foo bar" (7)
+	if len(lines) != 2 || overflow {
+		t.Errorf("Expected 2 lines, got %d (overflow: %v): %v", len(lines), overflow, lines)
+	}
+	if string(lines[0]) != "hello world " {
+		t.Errorf("Expected first line 'hello world ', got %q", string(lines[0]))
+	}
+	if string(lines[1]) != "foo bar" {
+		t.Errorf("Expected second line 'foo bar', got %q", string(lines[1]))
+	}
+
+	// No word boundary: a single long word falls back to character wrap
+	chars2 := ToChars([]byte("abcdefghijklmnop"))
+	lines2, _ := chars2.Lines(false, 100, 10, 0, 8, true)
+	if len(lines2) != 2 {
+		t.Errorf("Expected 2 lines for long word, got %d: %v", len(lines2), lines2)
+	}
+	if string(lines2[0]) != "abcdefghij" {
+		t.Errorf("Expected first line 'abcdefghij', got %q", string(lines2[0]))
+	}
+
+	// Tab as word boundary
+	chars3 := ToChars([]byte("hello\tworld"))
+	lines3, _ := chars3.Lines(false, 100, 7, 0, 8, true)
+	// "hello\t" should break at tab (width of tab at pos 5 with tabstop 8 = 3, total width = 8 > 7)
+	// Actually RunesWidth: 'h'=1,'e'=1,'l'=1,'l'=1,'o'=1,'\t'=3 = 8 > 7, overflowIdx=5
+	// Then word-wrap scans back and finds no space/tab before idx 5 (tab IS at idx 5 but we check line[k-1])
+	// Wait - let me think: overflowIdx=5, we check k=5 -> line[4]='o', k=4 -> line[3]='l'... no space/tab found
+	// Falls back to character wrap: "hello" | "\tworld"
+	if len(lines3) < 2 {
+		t.Errorf("Expected at least 2 lines for tab test, got %d: %v", len(lines3), lines3)
+	}
+
+	// wrapWord=false still character-wraps
+	chars4 := ToChars([]byte("hello world"))
+	lines4, _ := chars4.Lines(false, 100, 8, 0, 8, false)
+	if len(lines4) != 2 {
+		t.Errorf("Expected 2 lines with wrapWord=false, got %d: %v", len(lines4), lines4)
+	}
+	if string(lines4[0]) != "hello wo" {
+		t.Errorf("Expected first line 'hello wo', got %q", string(lines4[0]))
+	}
+}