From 3c34dd82750ca61a1ee7f329ed47fe01e6d1ee30 Mon Sep 17 00:00:00 2001
From: Junegunn Choi <junegunn.c@gmail.com>
Date: Fri, 17 Mar 2023 13:22:20 +0900
Subject: [PATCH] Fix extra new line in the preview window

When a colored text ends at the right end of the window

Fix #3209
---
 src/terminal.go | 14 ++++++++------
 test/test_go.rb | 17 +++++++++++++++++
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/src/terminal.go b/src/terminal.go
index 21400378..0310a9f0 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -1828,12 +1828,14 @@ func (t *Terminal) renderPreviewText(height int, lines []string, lineNo int, unc
 					trimmed, isTrimmed = t.trimRight(trimmed, maxWidth-t.pwindow.X())
 				}
 				str, width := t.processTabs(trimmed, prefixWidth)
-				prefixWidth += width
-				if t.theme.Colored && ansi != nil && ansi.colored() {
-					lbg = ansi.lbg
-					fillRet = t.pwindow.CFill(ansi.fg, ansi.bg, ansi.attr, str)
-				} else {
-					fillRet = t.pwindow.CFill(tui.ColPreview.Fg(), tui.ColPreview.Bg(), tui.AttrRegular, str)
+				if width > prefixWidth {
+					prefixWidth = width
+					if t.theme.Colored && ansi != nil && ansi.colored() {
+						lbg = ansi.lbg
+						fillRet = t.pwindow.CFill(ansi.fg, ansi.bg, ansi.attr, str)
+					} else {
+						fillRet = t.pwindow.CFill(tui.ColPreview.Fg(), tui.ColPreview.Bg(), tui.AttrRegular, str)
+					}
 				}
 				return !isTrimmed &&
 					(fillRet == tui.FillContinue || t.previewOpts.wrap && fillRet == tui.FillNextLine)
diff --git a/test/test_go.rb b/test/test_go.rb
index 6ef2d62c..07a7c195 100755
--- a/test/test_go.rb
+++ b/test/test_go.rb
@@ -2656,6 +2656,23 @@ class TestGoFZF < TestBase
     tmux.send_keys :Enter
     tmux.until { |lines| assert_equal 99, lines.item_count }
   end
+
+  def test_no_extra_newline_issue_3209
+    tmux.send_keys(%(seq 100 | #{FZF} --height 10 --preview-window up,wrap --preview 'printf "─%.0s" $(seq 1 "$((FZF_PREVIEW_COLUMNS - 5))"); printf $"\\e[7m%s\\e[0m" title; echo; echo something'), :Enter)
+    expected = <<~OUTPUT
+      ╭──────────
+      │ ─────────
+      │ something
+      │
+      ╰──────────
+        3
+        2
+      > 1
+        100/100 ─
+      >
+    OUTPUT
+    tmux.until { assert_block(expected, _1) }
+  end
 end
 
 module TestShell