feat(nvim_open_term): convert LF => CRLF (#26384)

Problem:
Unlike termopen(), nvim_open_term() PTYs do not carriage-return the
cursor on newline ("\n") input.

    nvim --clean
    :let chan_id = nvim_open_term(1, {})
    :call chansend(chan_id, ["here", "are", "some", "lines"])

Actual behavior:

    here
        are
           some
               lines

Expected behaviour:

    here
    are
    some
    lines

Solution:
Add `force_crlf` option, and enable it by default.

1 files changed, 51 insertions, 0 deletions

diff --git a/test/functional/terminal/channel_spec.lua b/test/functional/terminal/channel_spec.lua
index 6fb1a21561..b9abcd61c8 100644
--- a/test/functional/terminal/channel_spec.lua
+++ b/test/functional/terminal/channel_spec.lua
@@ -192,4 +192,55 @@ describe('no crash when TermOpen autocommand', function()
     ]]}
     assert_alive()
   end)
+
+  it('nvim_open_term({force_crlf=true}) converts newlines', function()
+    local buf = meths.create_buf(false, true)
+    local win = meths.get_current_win()
+    local term = meths.open_term(buf, {force_crlf = true})
+    screen:try_resize(8, 10)
+    meths.win_set_buf(win, buf)
+    meths.chan_send(term, 'here\nthere\nfoo\r\nbar\n\ntest')
+    screen:expect{grid=[[
+      ^here        |
+      there       |
+      foo         |
+      bar         |
+                  |
+      test        |
+      {0:~           }|
+      {0:~           }|
+      {0:~           }|
+                  |
+    ]]}
+    meths.chan_send(term, '\nfirst')
+    screen:expect{grid=[[
+      ^here        |
+      there       |
+      foo         |
+      bar         |
+                  |
+      test        |
+      first       |
+      {0:~           }|
+      {0:~           }|
+                  |
+    ]]}
+    meths.buf_delete(buf, {force = true})
+    buf = meths.create_buf(false, true)
+    term = meths.open_term(buf, {force_crlf = false})
+    meths.win_set_buf(win, buf)
+    meths.chan_send(term, 'here\nthere')
+    screen:expect{grid=[[
+      ^here        |
+          there   |
+                  |
+                  |
+                  |
+                  |
+                  |
+                  |
+                  |
+                  |
+    ]]}
+  end)
 end)