From d8a1e7ca4e599c43dda1849a66b19d9fbff12310 Mon Sep 17 00:00:00 2001
From: Steven Arcangeli <stevearc@stevearc.com>
Date: Sun, 8 Jan 2023 22:12:17 -0800
Subject: [PATCH] fix: preserve alternate buffer when using floating window
 (#20)

---
 lua/oil/init.lua      |  4 +++-
 tests/altbuf_spec.lua | 31 +++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/lua/oil/init.lua b/lua/oil/init.lua
index d575181..68894b8 100644
--- a/lua/oil/init.lua
+++ b/lua/oil/init.lua
@@ -388,8 +388,10 @@ M.select = function(opts)
       vertical = opts.vertical,
       horizontal = opts.horizontal,
       split = opts.split,
-      keepalt = true,
     }
+    if vim.tbl_isempty(mods) then
+      mods = nil
+    end
     local cmd = opts.split and "split" or "edit"
     vim.cmd({
       cmd = cmd,
diff --git a/tests/altbuf_spec.lua b/tests/altbuf_spec.lua
index 05726a9..d68ebbf 100644
--- a/tests/altbuf_spec.lua
+++ b/tests/altbuf_spec.lua
@@ -46,4 +46,35 @@ describe("Alternate buffer", function()
     vim.cmd.edit({ args = { "bar" } })
     assert.equals("foo", vim.fn.expand("#"))
   end)
+
+  describe("floating window", function()
+    it("sets previous buffer as alternate", function()
+      vim.cmd.edit({ args = { "foo" } })
+      oil.open_float()
+      -- This is lazy, but testing the actual select logic is more difficult. We can simply
+      -- replicated it by closing the current window and then doing the edit
+      vim.api.nvim_win_close(0, true)
+      vim.cmd.edit({ args = { "bar" } })
+      assert.equals("foo", vim.fn.expand("#"))
+    end)
+
+    it("preserves alternate buffer if editing the same file", function()
+      vim.cmd.edit({ args = { "foo" } })
+      vim.cmd.edit({ args = { "bar" } })
+      oil.open_float()
+      -- This is lazy, but testing the actual select logic is more difficult. We can simply
+      -- replicated it by closing the current window and then doing the edit
+      vim.api.nvim_win_close(0, true)
+      vim.cmd.edit({ args = { "bar" } })
+      assert.equals("foo", vim.fn.expand("#"))
+    end)
+
+    it("preserves alternate buffer if discarding changes", function()
+      vim.cmd.edit({ args = { "foo" } })
+      vim.cmd.edit({ args = { "bar" } })
+      oil.open_float()
+      oil.close()
+      assert.equals("foo", vim.fn.expand("#"))
+    end)
+  end)
 end)