Introduce g:startify_session_remove_lines

References #159.

autoload/startify.vim

@@ -251,14 +251,27 @@ function! startify#session_write(spath)
     let &sessionoptions = ssop
   endtry
 
-  if exists('g:startify_session_savevars') || exists('g:startify_session_savecmds')
+  if exists('g:startify_session_remove_lines')
+        \ || exists('g:startify_session_savevars')
+        \ || exists('g:startify_session_savecmds')
     execute 'split' a:spath
 
+    " remove lines from the session file
+    if exists('g:startify_session_remove_lines')
+      for pattern in g:startify_session_remove_lines
+        execute 'silent global/'. pattern .'/delete'
+      endfor
+    endif
+
     " put existing variables from savevars into session file
-    call append(line('$')-3, map(filter(copy(get(g:, 'startify_session_savevars', [])), 'exists(v:val)'), '"let ". v:val ." = ". strtrans(string(eval(v:val)))'))
+    if exists('g:startify_session_savevars')
+      call append(line('$')-3, map(filter(copy(g:startify_session_savevars), 'exists(v:val)'), '"let ". v:val ." = ". strtrans(string(eval(v:val)))'))
+    endif
 
     " put commands from savecmds into session file
-    call append(line('$')-3, get(g:, 'startify_session_savecmds', []))
+    if exists('g:startify_session_savecmds')
+      call append(line('$')-3, g:startify_session_savecmds)
+    endif
 
     setlocal bufhidden=delete
     silent update

doc/startify.txt

@@ -103,6 +103,7 @@ default values.
     |g:startify_session_delete_buffers|
     |g:startify_session_dir|
     |g:startify_session_persistence|
+    |g:startify_session_remove_lines|
     |g:startify_session_savecmds|
     |g:startify_session_savevars|
     |g:startify_skiplist_server|
@@ -307,6 +308,28 @@ Currently this option does this:
     - don't check every file if it's readable (stat(2))
     - don't filter through the bookmark list
 
+------------------------------------------------------------------------------
+                                               *g:startify_session_remove_lines*
+>
+    let g:startify_session_remove_lines = []
+<
+Lines matching any of the patterns in this list, will be removed from the
+session file.
+
+Example:
+>
+    let g:startify_session_remove_lines = ['setlocal', 'winheight']
+<
+Internally this simply does:
+>
+    :global/setlocal/delete
+    :global/winheight/delete
+<
+So you can use any |pattern|.
+
+NOTE: Take care not to mess up any expressions within the session file,
+otherwise you'll probably get problems when trying to load it.
+
 ------------------------------------------------------------------------------
                                                    *g:startify_session_savevars*
 >