Render preview label if possible when --preview-border=line

# Indent the header to align with the entries in the list
  fzf --header 'Hello' --header-border --list-border

  # No extra indentation required
  fzf --header 'Hello' --header-border

src/terminal.go

@@ -2014,7 +2014,9 @@ func (t *Terminal) resizeWindows(forcePreview bool, redrawBorder bool) {
 	// Print border label
 	t.printLabel(t.wborder, t.listLabel, t.listLabelOpts, t.listLabelLen, t.listBorderShape, false)
 	t.printLabel(t.border, t.borderLabel, t.borderLabelOpts, t.borderLabelLen, t.borderShape, false)
-	t.printLabel(t.pborder, t.previewLabel, t.previewLabelOpts, t.previewLabelLen, t.activePreviewOpts.border, false)
+	if t.pborder != nil && t.pwindow.Height() != t.pborder.Height() { // To address --preview-border=line with different positions
+		t.printLabel(t.pborder, t.previewLabel, t.previewLabelOpts, t.previewLabelLen, t.activePreviewOpts.border, false)
+	}
 	t.printLabel(t.inputBorder, t.inputLabel, t.inputLabelOpts, t.inputLabelLen, t.inputBorderShape, false)
 	t.printLabel(t.headerBorder, t.headerLabel, t.headerLabelOpts, t.headerLabelLen, t.headerBorderShape, false)
 }
@@ -2029,7 +2031,7 @@ func (t *Terminal) printLabel(window tui.Window, render labelPrinter, opts label
 	}
 
 	switch borderShape {
-	case tui.BorderHorizontal, tui.BorderTop, tui.BorderBottom, tui.BorderRounded, tui.BorderSharp, tui.BorderBold, tui.BorderBlock, tui.BorderThinBlock, tui.BorderDouble:
+	case tui.BorderHorizontal, tui.BorderTop, tui.BorderBottom, tui.BorderRounded, tui.BorderSharp, tui.BorderBold, tui.BorderBlock, tui.BorderThinBlock, tui.BorderDouble, tui.BorderLine:
 		if redrawBorder {
 			window.DrawHBorder()
 		}
@@ -2386,7 +2388,11 @@ func (t *Terminal) printHeaderImpl() {
 	}
 	// Wrapping is not supported for header
 	wrap := t.wrap
-	indent := strings.Repeat(" ", t.pointerLen+t.markerLen)
+	indentSize := t.pointerLen + t.markerLen
+	if t.headerBorderShape.HasLeft() && !t.listBorderShape.HasLeft() {
+		indentSize = util.Max(0, indentSize-(1+t.borderWidth))
+	}
+	indent := strings.Repeat(" ", indentSize)
 	t.wrap = false
 	for idx, lineStr := range append(append([]string{}, t.header0...), t.header...) {
 		line := idx

test/test_go.rb

@@ -3588,9 +3588,9 @@ class TestGoFZF < TestBase
       │     11
       │   > 10
       │   ┌────────
-      │   │   3
+      │   │ 3
-      │   │   2
+      │   │ 2
-      │   │   1
+      │   │ 1
       │   └header──
       │     19/97 ─
       │   > 1
@@ -3609,9 +3609,9 @@ class TestGoFZF < TestBase
       │     19/97 ─
       │   > 1
       │   ┌────────
-      │   │   3
+      │   │ 3
-      │   │   2
+      │   │ 2
-      │   │   1
+      │   │ 1
       │   └header──
       │
       ╰────────────