refactor(win_close): remove "force", don't pass on "free_buf" (#21921)

Problem:
The "force" flag of win_close() complicates the code and adds edge cases
where it is not clear what the correct behavior should be.
The "free_buf" flag of win_close() is passed on to float windows when
closing the last window of a tabpage, which doesn't make much sense.

Solution:
Remove the "force" flag and always close float windows as if :close! is
used when closing the last window of a tabpage, and set the "free_buf"
flag for a float window based on whether its buffer can be freed.
As 'hidden' is on by default, this change shouldn't affect many people.

1 files changed, 24 insertions, 22 deletions

diff --git a/test/functional/ui/float_spec.lua b/test/functional/ui/float_spec.lua
index 6759510ad1..60952543e7 100644
--- a/test/functional/ui/float_spec.lua
+++ b/test/functional/ui/float_spec.lua
@@ -462,6 +462,9 @@ describe('float window', function()
       end)
     end)
     describe("deleting the last non-floating window's buffer", function()
+      after_each(function()
+        eq(false, meths.buf_is_valid(old_buf))
+      end)
       describe('leaves one window with an empty buffer when there is only one buffer', function()
         local same_buf_float
         before_each(function()
@@ -552,6 +555,9 @@ describe('float window', function()
       end)
     end)
     describe('with splits, deleting the last listed buffer creates an empty buffer', function()
+      after_each(function()
+        eq(false, meths.buf_is_valid(old_buf))
+      end)
       describe('when a non-floating window has an unlisted buffer', function()
         local same_buf_float
         before_each(function()
@@ -597,6 +603,7 @@ describe('float window', function()
         same_buf_float = meths.open_win(old_buf, false, float_opts).id
       end)
       after_each(function()
+        eq(false, meths.buf_is_valid(old_buf))
         expect('')
         eq(2, #meths.list_wins())
         eq(2, #meths.list_tabpages())
@@ -629,6 +636,7 @@ describe('float window', function()
         same_buf_float = meths.open_win(old_buf, false, float_opts).id
       end)
       after_each(function()
+        eq(false, meths.buf_is_valid(old_buf))
         expect('')
         eq(3, #meths.list_wins())
         eq(2, #meths.list_tabpages())
@@ -656,12 +664,18 @@ describe('float window', function()
       old_win = curwin().id
     end)
     describe('closing the last non-floating window', function()
-      describe('closes the tabpage when all floating windows are closeable', function()
-        local same_buf_float
+      describe('closes the tabpage force-closing floating windows', function()
+        local same_buf_float, other_buf, other_buf_float
         before_each(function()
+          command('set nohidden')
           same_buf_float = meths.open_win(old_buf, false, float_opts).id
+          other_buf = meths.create_buf(true, false).id
+          other_buf_float = meths.open_win(other_buf, true, float_opts).id
+          insert('foo')
+          meths.set_current_win(old_win)
         end)
         after_each(function()
+          eq(true, meths.buf_is_valid(other_buf))
           eq(old_tabpage, curtab().id)
           expect('oldtab')
           eq(1, #meths.list_tabpages())
@@ -669,41 +683,30 @@ describe('float window', function()
         it('if called from non-floating window', function()
           meths.win_close(old_win, false)
         end)
-        it('if called from floating window', function()
+        it('if called from floating window with the same buffer', function()
           meths.set_current_win(same_buf_float)
           meths.win_close(old_win, false)
         end)
-      end)
-      describe('gives E5601 when there are non-closeable floating windows', function()
-        local other_buf_float
-        before_each(function()
-          command('set nohidden')
-          local other_buf = meths.create_buf(true, false).id
-          other_buf_float = meths.open_win(other_buf, true, float_opts).id
-          insert('foo')
-          meths.set_current_win(old_win)
-        end)
-        it('if called from non-floating window', function()
-          eq('Vim:E5601: Cannot close window, only floating window would remain',
-             pcall_err(meths.win_close, old_win, false))
-        end)
-        it('if called from floating window', function()
+        it('if called from floating window with another buffer', function()
           meths.set_current_win(other_buf_float)
-          eq('Vim:E5601: Cannot close window, only floating window would remain',
-             pcall_err(meths.win_close, old_win, false))
+          meths.win_close(old_win, false)
         end)
       end)
     end)
     describe("deleting the last non-floating window's buffer", function()
-      describe('closes the tabpage when all floating windows are closeable', function()
+      describe('closes the tabpage force-closing floating windows', function()
         local same_buf_float, other_buf, other_buf_float
         before_each(function()
+          command('set nohidden')
           same_buf_float = meths.open_win(old_buf, false, float_opts).id
           other_buf = meths.create_buf(true, false).id
           other_buf_float = meths.open_win(other_buf, true, float_opts).id
+          insert('foo')
           meths.set_current_win(old_win)
         end)
         after_each(function()
+          eq(false, meths.buf_is_valid(old_buf))
+          eq(true, meths.buf_is_valid(other_buf))
           eq(old_tabpage, curtab().id)
           expect('oldtab')
           eq(1, #meths.list_tabpages())
@@ -721,7 +724,6 @@ describe('float window', function()
           meths.buf_delete(old_buf, {force = false})
         end)
       end)
-      -- TODO: what to do when there are non-closeable floating windows?
     end)
   end)