Fix tab width when --frozen-left is used

#4703 (comment)

Author: junegunn

src/terminal.go

@@ -3905,6 +3905,7 @@ func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMat
 			frozenRight = line[splitOffsetRight:]
 		}
 		displayWidthSum := 0
+		displayWidthLeft := 0
 		todo := [3]func(){}
 		for fidx, runes := range [][]rune{frozenLeft, frozenRight, middle} {
 			if len(runes) == 0 {
@@ -3930,7 +3931,11 @@ func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMat
 				// For frozen parts, reserve space for the ellipsis in the middle part
 				adjustedMaxWidth -= ellipsisWidth
 			}
-			displayWidth = t.displayWidthWithLimit(runes, 0, adjustedMaxWidth)
+			var prefixWidth int
+			if fidx == 2 {
+				prefixWidth = displayWidthLeft
+			}
+			displayWidth = t.displayWidthWithLimit(runes, prefixWidth, adjustedMaxWidth)
 			if !t.wrap && displayWidth > adjustedMaxWidth {
 				maxe = util.Constrain(maxe+min(maxWidth/2-ellipsisWidth, t.hscrollOff), 0, len(runes))
 				transformOffsets := func(diff int32) {
@@ -3968,14 +3973,17 @@ func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMat
 				displayWidth = t.displayWidthWithLimit(runes, 0, maxWidth)
 			}
 			displayWidthSum += displayWidth
+			if fidx == 0 {
+				displayWidthLeft = displayWidth
+			}
 
 			if maxWidth > 0 {
 				color := colBase
 				if hidden {
 					color = color.WithFg(t.theme.Nomatch)
 				}
 				todo[fidx] = func() {
-					t.printColoredString(t.window, runes, offs, color)
+					t.printColoredString(t.window, runes, offs, color, prefixWidth)
 				}
 			} else {
 				break
@@ -4002,10 +4010,13 @@ func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMat
 	return finalLineNum
 }
 
-func (t *Terminal) printColoredString(window tui.Window, text []rune, offsets []colorOffset, colBase tui.ColorPair) {
+func (t *Terminal) printColoredString(window tui.Window, text []rune, offsets []colorOffset, colBase tui.ColorPair, initialPrefixWidth ...int) {
 	var index int32
 	var substr string
 	var prefixWidth int
+	if len(initialPrefixWidth) > 0 {
+		prefixWidth = initialPrefixWidth[0]
+	}
 	maxOffset := int32(len(text))
 	var url *url
 	for _, offset := range offsets {

test/test_core.rb

@@ -1190,6 +1190,16 @@ def test_keep_right
     tmux.until { |lines| assert lines.any_include?('9999␊10000') }
   end
 
+  def test_freeze_left_tabstop
+    writelines(["1\t2\t3"])
+    # With --freeze-left 1 and --tabstop=2:
+    # Frozen left: "1" (width 1)
+    # Middle starts with "\t" at prefix width 1, tabstop 2 → 1 space
+    # Then "2" at column 2, next "\t" at column 3 → 1 space, then "3"
+    tmux.send_keys %(cat #{tempname} | #{FZF} --tabstop=2 --freeze-left 1), :Enter
+    tmux.until { |lines| assert_equal '> 1 2 3', lines[-3] }
+  end
+
   def test_freeze_left_keep_right
     tmux.send_keys %(seq 10000 | #{FZF} --read0 --delimiter "\n" --freeze-left 3 --keep-right --ellipsis XX --no-multi-line --bind space:toggle-multi-line), :Enter
     tmux.until { |lines| assert_match(/^> 1␊2␊3XX.*10000␊$/, lines[-3]) }