Fix undo and partial format

Author: Ram-Z

autoload/clang_format.vim

@@ -205,7 +205,7 @@ function! s:detect_style_file() abort
 endfunction
 
 function! clang_format#format(line1, line2) abort
-    let args = printf(' -lines=%d:%d', a:line1, a:line2)
+    let args = ""
     if ! (g:clang_format#detect_style_file && s:detect_style_file())
         let args .= printf(' -style=%s ', s:make_style_options())
     else
@@ -217,8 +217,7 @@ function! clang_format#format(line1, line2) abort
     endif
     let args .= g:clang_format#extra_args
     let clang_format = printf('%s %s --', s:shellescape(g:clang_format#command), args)
-    let source = join(getline(1, '$'), "\n")
-    return s:system(clang_format, source)
+    return s:system(clang_format, join(getline(a:line1, a:line2), "\n"))
 endfunction
 " }}}
 
@@ -238,8 +237,12 @@ function! clang_format#replace(line1, line2, ...) abort
     try
         let formatted = clang_format#format(a:line1, a:line2)
         if s:success(formatted)
+            let indent = indent(a:line1) / shiftwidth()
+            silent exe a:line1.','a:line2.'delete _'
+
             call setreg('g', formatted, 'V')
-            silent keepjumps normal! gg0VG"gp
+            silent put! g
+            silent exe "'[,']".repeat('>', indent)
         else
             call s:error_message(formatted)
         endif