Fix adaptive height with an inline header or footer border

- extraLines() used borderLines(), which reports zero for BorderInline
- Divider drawn for an inline section still takes a line, and
  resizeWindows() reserves it via addInline()
- So adaptive height came up one line short per inline section and the
  list scrolled
- Affects --header-lines-border, --header-border and --footer-border
  alike. All three set came up three lines short
- Without a list border the shape normalizes to BorderTop or BorderBottom,
  which report a line, hence --no-list-border looked like a fix

    seq 10 | fzf --height=~100% --list-border \
                 --header-lines=1 --header-lines-border=inline

Fix #4904

CHANGELOG.md

@@ -6,6 +6,8 @@ CHANGELOG
 - Fixed an escape sequence split across reads being parsed as a fragment, which leaked the rest into the query (#4899)
     - e.g. A terminal answering the startup `DECRQM` query late left `?2004;2$y`, CTRL-UP left `5A`, and SGR mouse input left `0;1;1M`
 - Fixed `--tiebreak=pathname` not detecting the last path separator when the line contains a non-ASCII character before it (#4902)
+- Fixed adaptive height not reserving a line for the divider of an inline header or footer border, so the list came up one line short for each of them (#4904)
+    - e.g. `seq 10 | fzf --height=~100% --list-border --header-lines=1 --header-lines-border=inline`
 - Vim plugin
     - fzf no longer blocks the editor, so live previews keep working while fzf is open
         - `fzf#run` returns an empty list when it runs fzf asynchronously. Use `sink`, `sinklist`, or `exit` to get the result

src/terminal.go

@@ -1547,6 +1547,14 @@ func (t *Terminal) visibleInputLinesInList() int {
 
 // Extra number of lines needed to display fzf
 func (t *Terminal) extraLines() int {
+	// borderLines() reports zero for BorderInline, but addInline() still
+	// reserves a divider line for it
+	sectionLines := func(shape tui.BorderShape) int {
+		if shape == tui.BorderInline {
+			return 1
+		}
+		return borderLines(shape)
+	}
 	extra := 0
 	if !t.inputless {
 		extra++
@@ -1562,16 +1570,16 @@ func (t *Terminal) extraLines() int {
 	}
 	if t.headerVisible {
 		if t.hasHeaderWindow() {
-			extra += borderLines(t.headerBorderShape)
+			extra += sectionLines(t.headerBorderShape)
 		}
 		extra += len(t.header0)
 		if w, shape := t.determineHeaderLinesShape(); w {
-			extra += borderLines(shape)
+			extra += sectionLines(shape)
 		}
 		extra += t.headerLines
 	}
 	if len(t.footer) > 0 {
-		extra += borderLines(t.footerBorderShape)
+		extra += sectionLines(t.footerBorderShape)
 		extra += len(t.footer)
 	}
 	return extra

test/test_layout.rb

@@ -882,6 +882,28 @@ class TestLayout < TestInteractive
     tmux.until { assert_block(block, it) }
   end
 
+  def test_adaptive_height_with_inline_sections
+    tmux.send_keys %(seq 10 | #{FZF} --height=~100% --list-border --header-lines=1 --header-lines-border=inline), :Enter
+    block = <<~BLOCK
+      ╭──────
+      │   10
+      │   9
+      │   8
+      │   7
+      │   6
+      │   5
+      │   4
+      │   3
+      │ > 2
+      ├──────
+      │   1
+      ╰──────
+          9/9
+        >
+    BLOCK
+    tmux.until { assert_block(block, it) }
+  end
+
   def test_style_full_adaptive_height
     tmux.send_keys %(seq 1| #{FZF} --style=full:rounded --height=~100% --header-lines=1 --info=default), :Enter
     block = <<~BLOCK