From 1cbe9057efb5f9e820d9971e3810b6c3caf1bf43 Mon Sep 17 00:00:00 2001
From: Jerome Reybert <jreybert@gmail.com>
Date: Sat, 18 Dec 2021 22:48:19 +0100
Subject: [PATCH] Add option to trim last empty line

This new feature fixes a behavior difference between vim-clang-format
and clang-format.

If the 'to be formatted' buffer ends with one or several empty lines,
vim-clang-format keeps one final empty line. clang-format does not let
any empty line.

If the 'to be formatted' buffer ends with a non empty line, both
vim-clang-format and clang-format produce the same result, a code
finishing with the non empty line.

This problem seems to have been a problem for other clang plugin, in
other editors, eg in VisualCode:
https://stackoverflow.com/questions/55374304/add-a-single-empty-line-as-the-last-line-in-the-code-clang-format

The culprit in vim-clang-format is the `split()` function: as the
`formatted` string ends with a newline, it generates a List with a last
empty item.
---
 autoload/clang_format.vim |  4 ++++
 doc/clang-format.txt      | 10 +++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/autoload/clang_format.vim b/autoload/clang_format.vim
index f4ff380..652a728 100644
--- a/autoload/clang_format.vim
+++ b/autoload/clang_format.vim
@@ -200,6 +200,7 @@ let g:clang_format#filetype_style_options = s:getg('clang_format#filetype_style_
 
 let g:clang_format#detect_style_file = s:getg('clang_format#detect_style_file', 1)
 let g:clang_format#enable_fallback_style = s:getg('clang_format#enable_fallback_style', 1)
+let g:clang_format#trim_last_empty_line = s:getg('clang_format#trim_last_empty_line', 0)
 
 let g:clang_format#auto_format = s:getg('clang_format#auto_format', 0)
 let g:clang_format#auto_format_git_diff = s:getg('clang_format#auto_format_git_diff', 0)
@@ -260,6 +261,9 @@ function! clang_format#replace_ranges(ranges, ...) abort
     endif
 
     let winview = winsaveview()
+    if g:clang_format#trim_last_empty_line
+        let formatted = trim(formatted, "\n", 2)
+    endif
     let splitted = split(formatted, '\n', 1)
 
     silent! undojoin
diff --git a/doc/clang-format.txt b/doc/clang-format.txt
index eb3b6b3..b13ec63 100644
--- a/doc/clang-format.txt
+++ b/doc/clang-format.txt
@@ -240,7 +240,15 @@ g:clang_format#enable_fallback_style	  *g:clang_format#enable_fallback_style*
     ".clang-format" is not found.
     The default value is 1.
 
-
+g:clang_format#trim_last_empty_line        *g:clang_format#trim_last_empty_line*
+
+    If the initial buffer ends with one or more empty lines, vim-clang-format
+    will let one single empty line. This is not the clang-format behavior,
+    which do not let any empty line at the end of the file.
+    When the value is 1, vim-clang-format ensures that formatted buffer does
+    end with any empty lines.
+    The default value is 0 (which is the historical vim-clang-format
+    behavior).
 
 ==============================================================================
 SETUP EXAMPLE                                   *vim-clang-format-setup-example*