Bug fix: Re-implement Vim's special handling of initial, empty buffer

See issue #60 on GitHub:
  #60

This is a follow up to my recent changes for issue #28:

  Bug fix: Disable Vim's special handling of initial, empty buffer
  #28

Author: xolox

README.md

@@ -236,9 +236,9 @@ Recently this plug-in switched from reimplementing [:mksession][mksession] to ac
 <!-- Start of generated documentation -->
 
 The documentation of the 34 functions below was extracted from
-2 Vim scripts on June 24, 2013 at 22:49.
+1 Vim scripts on June 24, 2013 at 23:47.
 
-### Public API for vim-notes plug-in
+### Public API for the vim-notes plug-in
 
 #### The `xolox#session#save_session()` function
 

autoload/xolox/session.vim

@@ -1,19 +1,13 @@
-" Public API for vim-notes plug-in.
+" Public API for the vim-notes plug-in.
 "
 " Author: Peter Odding
 " Last Change: June 24, 2013
 " URL: http://peterodding.com/code/vim/session/
 
-let g:xolox#session#version = '2.4.3'
+let g:xolox#session#version = '2.4.4'
 
 " Public API for session persistence. {{{1
 
-" The functions in this fold take a single list argument in which the Vim
-" script lines are stored that should be executed to restore the (relevant
-" parts of the) current Vim editing session. The only exception to this is
-" xolox#session#save_session() which expects the target filename as 2nd
-" argument:
-
 function! xolox#session#save_session(commands, filename) " {{{2
   " Save the current Vim editing session to a Vim script using the
   " [:mksession] [] command and some additional Vim magic provided by the
@@ -193,6 +187,15 @@ function! xolox#session#save_state(commands) " {{{2
       call map(lines, 's:tabpage_filter(buffers, v:val)')
     endif
     call extend(a:commands, map(lines, 's:state_filter(v:val)'))
+    " Re-implement Vim's special handling of the initial, empty buffer.
+    call add(a:commands, "if exists('s:wipebuf')")
+    call add(a:commands, "  if empty(bufname(s:wipebuf)) && !getbufvar(s:wipebuf, '&modified')")
+    call add(a:commands, "    let s:wipebuflines = getbufline(s:wipebuf, 1, '$')")
+    call add(a:commands, "    if len(s:wipebuflines) <= 1 && empty(get(s:wipebuflines, 0, ''))")
+    call add(a:commands, "      silent exe 'bwipe ' . s:wipebuf")
+    call add(a:commands, "    endif")
+    call add(a:commands, "  endif")
+    call add(a:commands, "endif")
     return 1
   finally
     let &sessionoptions = ssop_save
@@ -252,7 +255,7 @@ function! s:state_filter(line) " {{{3
     " when :mksession adds corresponding :argglobal and/or :argument commands
     " to the session script.
     return '" ' . a:line
-  elseif a:line =~ "^\\s*silent exe 'bwipe ' \\. s:wipebuf$"
+  elseif a:line =~ "^\\s*silent exe 'bwipe ' \\. s:wipebuf$" || a:line =~ '^unlet! s:wipebuf$'
     " Disable Vim's special handling of the initial, empty buffer because it
     " breaks restoring of special windows with content generated by a Vim
     " plug-in. The :mksession command doesn't have this problem because it

doc/session.txt

@@ -34,7 +34,7 @@ Contents ~
  5. Compatibility with other plug-ins |session-compatibility-with-other-plug-ins|
  6. Known issues                                         |session-known-issues|
  7. Function reference                             |session-function-reference|
-  1. Public API for vim-notes plug-in |session-public-api-for-vim-notes-plug-in|
+  1. Public API for the vim-notes plug-in |session-public-api-for-vim-notes-plug-in|
    1. The |xolox#session#save_session()| function
    2. The |xolox#session#save_globals()| function
    3. The |xolox#session#save_features()| function
@@ -476,12 +476,12 @@ might take a while...)
                                                    *session-function-reference*
 Function reference ~
 
-The documentation of the 34 functions below was extracted from 2 Vim scripts on
-June 24, 2013 at 22:49.
+The documentation of the 34 functions below was extracted from 1 Vim scripts on
+June 24, 2013 at 23:47.
 
 -------------------------------------------------------------------------------
                                      *session-public-api-for-vim-notes-plug-in*
-Public API for vim-notes plug-in ~
+Public API for the vim-notes plug-in ~
 
 -------------------------------------------------------------------------------
 The *xolox#session#save_session()* function