patch to fix live preview

a.patch

diff --git a/plugin/latexlivepreview.vim b/plugin/latexlivepreview.vim
index 03a5df5..767b64e 100644
--- a/plugin/latexlivepreview.vim
+++ b/plugin/latexlivepreview.vim
@@ -90,9 +90,11 @@ vim.command("let b:livepreview_buf_data['tmp_dir'] = '" +
         tempfile.mkdtemp() + "'")
 EEOOFF
 
-    let b:livepreview_buf_data['tmp_src_file'] =
-                \ b:livepreview_buf_data['tmp_dir'] . '/' . expand('%:r') .
-                \ '.' . expand('%:e')
+    if !has_key(b:livepreview_buf_data, 'tmp_src_file')
+        let b:livepreview_buf_data['tmp_src_file'] =
+                    \ b:livepreview_buf_data['tmp_dir'] . '/' . expand('%:r') .
+                    \ '.' . expand('%:e')
+    endif
 
     silent exec 'write! ' . b:livepreview_buf_data['tmp_src_file']