From b1ec1e8544af9357ff26f4cab97f0e250435cbed Mon Sep 17 00:00:00 2001
From: Luke Kershaw <35707277+l-kershaw@users.noreply.github.com>
Date: Sun, 18 Jul 2021 17:59:17 +0100
Subject: [PATCH 1/4] fix: check if tabline is present when calculating certain
 layouts

- also tweaks height calculation for `center` strategy
---
 lua/telescope/pickers/layout_strategies.lua | 44 +++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/lua/telescope/pickers/layout_strategies.lua b/lua/telescope/pickers/layout_strategies.lua
index 43f90600fa..7869073645 100644
--- a/lua/telescope/pickers/layout_strategies.lua
+++ b/lua/telescope/pickers/layout_strategies.lua
@@ -245,11 +245,18 @@ layout_strategies.horizontal = make_documented_layout('horizontal', vim.tbl_exte
     preview_cutoff = "When columns are less than this value, the preview will be disabled",
     prompt_position = { "Where to place prompt window.", "Available Values: 'bottom', 'top'" },
 }), function(self, max_columns, max_lines, layout_config)
+
   local initial_options = p_window.get_initial_window_options(self)
   local preview = initial_options.preview
   local results = initial_options.results
   local prompt = initial_options.prompt
 
+  local tbln = (vim.o.showtabline == 2)
+    or (vim.o.showtabline == 1 and #vim.api.nvim_list_tabpages() > 1)
+  if tbln then
+    max_lines = max_lines - 1
+  end
+
   local width_opt = layout_config.width
   local picker_width = resolve.resolve_width(width_opt)(self, max_columns, max_lines)
   local width_padding = math.floor((max_columns - picker_width)/2)
@@ -306,6 +313,12 @@ layout_strategies.horizontal = make_documented_layout('horizontal', vim.tbl_exte
     error("Unknown prompt_position: " .. tostring(self.window.prompt_position) .. "\n" .. vim.inspect(layout_config))
   end
 
+  if tbln then
+    prompt.line = prompt.line + 1
+    results.line = results.line + 1
+    preview.line = preview.line + 1
+  end
+
   return {
     preview = self.previewer and preview.width > 0 and preview,
     results = results,
@@ -342,11 +355,18 @@ end)
 layout_strategies.center = make_documented_layout("center", vim.tbl_extend("error", shared_options, {
   preview_cutoff = "When lines are less than this value, the preview will be disabled",
 }), function(self, max_columns, max_lines,layout_config)
+
   local initial_options = p_window.get_initial_window_options(self)
   local preview = initial_options.preview
   local results = initial_options.results
   local prompt = initial_options.prompt
 
+  local tbln = (vim.o.showtabline == 2)
+    or (vim.o.showtabline == 1 and #vim.api.nvim_list_tabpages() > 1)
+  if tbln then
+    max_lines = max_lines - 1
+  end
+
   -- This sets the width for the whole layout
   local width_opt = layout_config.width
   local width = resolve.resolve_width(width_opt)(self, max_columns, max_lines)
@@ -354,6 +374,10 @@ layout_strategies.center = make_documented_layout("center", vim.tbl_extend("erro
   -- This sets the number of results displayed
   local res_height_opt = layout_config.height
   local res_height = resolve.resolve_height(res_height_opt)(self, max_columns, max_lines)
+  if type(res_height_opt) ~= "function"
+    and (type(res_height_opt) ~= "number" or res_height_opt < 1) then
+    res_height = res_height - 2
+  end
 
   local max_results = (res_height > max_lines and max_lines or res_height)
   local max_width = (width > max_columns and max_columns or width)
@@ -384,6 +408,12 @@ layout_strategies.center = make_documented_layout("center", vim.tbl_extend("erro
   prompt.col = results.col
   preview.col = results.col
 
+  if tbln then
+    prompt.line = prompt.line + 1
+    results.line = results.line + 1
+    preview.line = preview.line + 1
+  end
+
   return {
     preview = self.previewer and preview.height > 0 and preview,
     results = results,
@@ -416,6 +446,7 @@ layout_strategies.cursor = make_documented_layout("cursor", vim.tbl_extend("erro
     preview_width = { "Change the width of Telescope's preview window", "See |resolver.resolve_width()|", },
     preview_cutoff = "When columns are less than this value, the preview will be disabled",
 }), function(self, max_columns, max_lines, layout_config)
+
   local initial_options = p_window.get_initial_window_options(self)
   local preview = initial_options.preview
   local results = initial_options.results
@@ -512,11 +543,18 @@ layout_strategies.vertical = make_documented_layout("vertical", vim.tbl_extend("
   preview_height = { "Change the height of Telescope's preview window", "See |resolver.resolve_height()|" },
   prompt_position = { "(unimplemented, but we plan on supporting)" },
 }), function(self, max_columns, max_lines, layout_config)
+
   local initial_options = p_window.get_initial_window_options(self)
   local preview = initial_options.preview
   local results = initial_options.results
   local prompt = initial_options.prompt
 
+  local tbln = (vim.o.showtabline == 2)
+    or (vim.o.showtabline == 1 and #vim.api.nvim_list_tabpages() > 1)
+  if tbln then
+    max_lines = max_lines - 1
+  end
+
   local width_opt = layout_config.width
   local picker_width = resolve.resolve_width(width_opt)(self,max_columns,max_lines)
   local width_padding = math.floor((max_columns - picker_width)/2)
@@ -563,6 +601,12 @@ layout_strategies.vertical = make_documented_layout("vertical", vim.tbl_extend("
     prompt.line = results.line + results.height + 2
   end
 
+  if tbln then
+    prompt.line = prompt.line + 1
+    results.line = results.line + 1
+    preview.line = preview.line + 1
+  end
+
   return {
     preview = self.previewer and preview.height > 0 and preview,
     results = results,

From 3f835d59125706550a6c481a11f721c91a20d209 Mon Sep 17 00:00:00 2001
From: Luke Kershaw <35707277+l-kershaw@users.noreply.github.com>
Date: Sun, 18 Jul 2021 20:53:52 +0100
Subject: [PATCH 2/4] refactor: remove `center` strategy tweak

- will reimplement something similar in another PR for a few of the strategies
---
 lua/telescope/pickers/layout_strategies.lua | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/lua/telescope/pickers/layout_strategies.lua b/lua/telescope/pickers/layout_strategies.lua
index 7869073645..fa953cf305 100644
--- a/lua/telescope/pickers/layout_strategies.lua
+++ b/lua/telescope/pickers/layout_strategies.lua
@@ -374,10 +374,6 @@ layout_strategies.center = make_documented_layout("center", vim.tbl_extend("erro
   -- This sets the number of results displayed
   local res_height_opt = layout_config.height
   local res_height = resolve.resolve_height(res_height_opt)(self, max_columns, max_lines)
-  if type(res_height_opt) ~= "function"
-    and (type(res_height_opt) ~= "number" or res_height_opt < 1) then
-    res_height = res_height - 2
-  end
 
   local max_results = (res_height > max_lines and max_lines or res_height)
   local max_width = (width > max_columns and max_columns or width)

From 5142c7a2e85fc299514c8a45cbacbd86aeb75979 Mon Sep 17 00:00:00 2001
From: Luke Kershaw <35707277+l-kershaw@users.noreply.github.com>
Date: Mon, 19 Jul 2021 21:38:11 +0100
Subject: [PATCH 3/4] fix: check if `preview.line` is `nil`

---
 lua/telescope/pickers/layout_strategies.lua | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lua/telescope/pickers/layout_strategies.lua b/lua/telescope/pickers/layout_strategies.lua
index fa953cf305..f633a3e0d4 100644
--- a/lua/telescope/pickers/layout_strategies.lua
+++ b/lua/telescope/pickers/layout_strategies.lua
@@ -323,7 +323,7 @@ layout_strategies.horizontal = make_documented_layout('horizontal', vim.tbl_exte
     preview = self.previewer and preview.width > 0 and preview,
     results = results,
     prompt = prompt
-}
+  }
 end)
 
 --- Centered layout with a combined block of the prompt
@@ -600,7 +600,7 @@ layout_strategies.vertical = make_documented_layout("vertical", vim.tbl_extend("
   if tbln then
     prompt.line = prompt.line + 1
     results.line = results.line + 1
-    preview.line = preview.line + 1
+    preview.line = preview.line ~= nil and preview.line + 1
   end
 
   return {

From c14b48f3a4cc6c26f7b50508b53ee707029021ea Mon Sep 17 00:00:00 2001
From: Luke Kershaw <35707277+l-kershaw@users.noreply.github.com>
Date: Mon, 19 Jul 2021 22:56:03 +0100
Subject: [PATCH 4/4] refactor: factor out `tbln` calculation and `max_lines`
 adjustment

- also tweaked `vertical` calculations so that no `nil` check is required
---
 lua/telescope/pickers/layout_strategies.lua | 52 ++++++++++-----------
 1 file changed, 24 insertions(+), 28 deletions(-)

diff --git a/lua/telescope/pickers/layout_strategies.lua b/lua/telescope/pickers/layout_strategies.lua
index f633a3e0d4..4630a64d7c 100644
--- a/lua/telescope/pickers/layout_strategies.lua
+++ b/lua/telescope/pickers/layout_strategies.lua
@@ -46,6 +46,15 @@ local get_border_size = function(opts)
   return 1
 end
 
+local calc_tabline = function(max_lines)
+  local tbln = (vim.o.showtabline == 2)
+    or (vim.o.showtabline == 1 and #vim.api.nvim_list_tabpages() > 1)
+  if tbln then
+    max_lines = max_lines - 1
+  end
+  return max_lines, tbln
+end
+
 local layout_strategies = {}
 layout_strategies._configurations = {}
 
@@ -251,11 +260,8 @@ layout_strategies.horizontal = make_documented_layout('horizontal', vim.tbl_exte
   local results = initial_options.results
   local prompt = initial_options.prompt
 
-  local tbln = (vim.o.showtabline == 2)
-    or (vim.o.showtabline == 1 and #vim.api.nvim_list_tabpages() > 1)
-  if tbln then
-    max_lines = max_lines - 1
-  end
+  local tbln
+  max_lines, tbln = calc_tabline(max_lines)
 
   local width_opt = layout_config.width
   local picker_width = resolve.resolve_width(width_opt)(self, max_columns, max_lines)
@@ -361,11 +367,8 @@ layout_strategies.center = make_documented_layout("center", vim.tbl_extend("erro
   local results = initial_options.results
   local prompt = initial_options.prompt
 
-  local tbln = (vim.o.showtabline == 2)
-    or (vim.o.showtabline == 1 and #vim.api.nvim_list_tabpages() > 1)
-  if tbln then
-    max_lines = max_lines - 1
-  end
+  local tbln
+  max_lines, tbln = calc_tabline(max_lines)
 
   -- This sets the width for the whole layout
   local width_opt = layout_config.width
@@ -545,11 +548,8 @@ layout_strategies.vertical = make_documented_layout("vertical", vim.tbl_extend("
   local results = initial_options.results
   local prompt = initial_options.prompt
 
-  local tbln = (vim.o.showtabline == 2)
-    or (vim.o.showtabline == 1 and #vim.api.nvim_list_tabpages() > 1)
-  if tbln then
-    max_lines = max_lines - 1
-  end
+  local tbln
+  max_lines, tbln = calc_tabline(max_lines)
 
   local width_opt = layout_config.width
   local picker_width = resolve.resolve_width(width_opt)(self,max_columns,max_lines)
@@ -582,25 +582,21 @@ layout_strategies.vertical = make_documented_layout("vertical", vim.tbl_extend("
 
   results.col, preview.col, prompt.col = width_padding, width_padding, width_padding
 
-  if self.previewer then
-    if not layout_config.mirror then
-      preview.line = height_padding
-      results.line = preview.line + preview.height + 2
-      prompt.line = results.line + results.height + 2
-    else
-      prompt.line = height_padding
-      results.line = prompt.line + prompt.height + 2
-      preview.line = results.line + results.height + 2
-    end
-  else
-    results.line = height_padding
+  if not layout_config.mirror then
+    preview.line = height_padding
+    results.line = (preview.height == 0) and preview.line
+      or preview.line + preview.height + 2
     prompt.line = results.line + results.height + 2
+  else
+    prompt.line = height_padding
+    results.line = prompt.line + prompt.height + 2
+    preview.line = results.line + results.height + 2
   end
 
   if tbln then
     prompt.line = prompt.line + 1
     results.line = results.line + 1
-    preview.line = preview.line ~= nil and preview.line + 1
+    preview.line = preview.line + 1
   end
 
   return {