Make compatibility with miscellaneous scripts explicit

5 files changed, 93 insertions, 22 deletions

diff --git a/autoload/xolox/easytags.vim b/autoload/xolox/easytags.vim
index da73673..02ae1e5 100644
--- a/autoload/xolox/easytags.vim
+++ b/autoload/xolox/easytags.vim
@@ -1,9 +1,11 @@
 " Vim script
 " Author: Peter Odding <peter@peterodding.com>
-" Last Change: April 19, 2013
+" Last Change: April 20, 2013
 " URL: http://peterodding.com/code/vim/easytags/
 
-let g:xolox#easytags#version = '3.1.1'
+let g:xolox#easytags#version = '3.1.2'
+
+call xolox#misc#compat#check('easytags', 1)
 
 " Public interface through (automatic) commands. {{{1
 
diff --git a/autoload/xolox/misc/README.md b/autoload/xolox/misc/README.md
index 9111126..f375fe6 100644
--- a/autoload/xolox/misc/README.md
+++ b/autoload/xolox/misc/README.md
@@ -1,24 +1,49 @@
 # Miscellaneous auto-load Vim scripts
 
-The git repository at <http://github.com/xolox/vim-misc> contains Vim scripts that are used by most of the [Vim plug-ins I've written] [plugins] yet don't really belong with any single one. I include this repository as a subdirectory of my plug-in repositories using the following commands:
+The git repository at [github.com/xolox/vim-misc] [repository] contains Vim scripts that are used by most of the [Vim plug-ins I've written] [plugins] yet don't really belong with any single one. I include this repository as a subdirectory of my plug-in repositories using the following commands:
 
     $ git remote add -f vim-misc https://github.com/xolox/vim-misc.git
     $ git merge -s ours --no-commit vim-misc/master
     $ git read-tree --prefix=autoload/xolox/misc/ -u vim-misc/master
     $ git commit -m "Merge vim-misc repository as subdirectory"
 
-To update a plug-in repository to the latest versions of the miscellaneous auto-load scripts I execute the following command:
+The above trick is called the [subtree merge strategy] [merge-strategy]. To update a plug-in repository to the latest version of the miscellaneous auto-load scripts I execute the following command:
 
     $ git pull -s subtree vim-misc master
 
+## Why make things so complex?
+
+I came up with this solution after multiple years of back and forth between Vim Online users, the GitHub crowd and my own sanity:
+
+1. When I started publishing my first Vim plug-ins I would prepare ZIP archives for Vim Online using makefiles. The makefiles would make sure the miscellaneous scripts were included in the uploaded distributions. This had two disadvantages: It lost git history and the repositories on GitHub were not usable out of the box, so [I got complaints from GitHub (Pathogen) users] [github-complaints].
+
+2. My second attempt to solve the problem used git submodules which seemed like the ideal solution until I actually started doing it. Submodules are not initialized during a normal `git clone`, you need to use `git clone --recursive` instead but Vim plug-in managers like [Pathogen] [pathogen] and [Vundle] [vundle] don't do this (at least [they didn't when I tried] [vundle-discussion]) so people would end up with broken checkouts.
+
+3. After finding out that git submodules were not going to solve my problems I searched for other inclusion strategies supported by git. After a while I came upon the [subtree merge strategy] [merge-strategy] which I have been using for more than two years now.
+
+## Compatibility issues
+
+Regardless of the inclusion strategies discussed above, my current scheme has a flaw: If more than one of my plug-ins are installed in a Vim profile using [Pathogen] [pathogen] or [Vundle] [vundle], the miscellaneous autoload scripts will all be loaded from the subdirectory of one single plug-in.
+
+This means that when I break compatibility in the miscellaneous scripts, I have to make sure to merge the changes into all of my plug-ins. Even then, if a user has more than one of my plug-ins installed but updates only one of them, the other plug-ins (that are not yet up to date) can break (because of the backwards incompatible change).
+
+The `xolox#misc#compat#check()` function makes sure that incompatibilities are detected early so that the user knows which plug-in to update if incompatibilities arise.
+
 ## Contact
 
 If you have questions, bug reports, suggestions, etc. the author can be contacted at <peter@peterodding.com>. The latest version is available at <http://peterodding.com/code/vim/misc> and <http://github.com/xolox/vim-misc>.
 
 ## License
 
-This software is licensed under the [MIT license](http://en.wikipedia.org/wiki/MIT_License).  
-© 2011 Peter Odding &lt;<peter@peterodding.com>&gt;.
+This software is licensed under the [MIT license] [mit].  
+© 2013 Peter Odding &lt;<peter@peterodding.com>&gt;.
 
 
+[github-complaints]: https://github.com/xolox/vim-easytags/issues/1
+[merge-strategy]: http://www.kernel.org/pub/software/scm/git/docs/howto/using-merge-subtree.html
+[mit]: http://en.wikipedia.org/wiki/MIT_License
+[pathogen]: http://www.vim.org/scripts/script.php?script_id=2332
 [plugins]: http://peterodding.com/code/vim/
+[repository]: https://github.com/xolox/vim-misc
+[vundle-discussion]: https://github.com/gmarik/vundle/pull/41
+[vundle]: https://github.com/gmarik/vundle
diff --git a/autoload/xolox/misc/buffer.vim b/autoload/xolox/misc/buffer.vim
index e4472e6..3597cc2 100644
--- a/autoload/xolox/misc/buffer.vim
+++ b/autoload/xolox/misc/buffer.vim
@@ -1,37 +1,51 @@
 " Vim auto-load script
 " Author: Peter Odding <peter@peterodding.com>
-" Last Change: September 4, 2011
+" Last Change: April 18, 2013
 " URL: http://peterodding.com/code/vim/misc/
 
-function! xolox#misc#buffer#is_empty()
+function! xolox#misc#buffer#is_empty() " {{{1
   " Check if the current buffer is an empty, unchanged buffer which can be reused.
   return !&modified && expand('%') == '' && line('$') <= 1 && getline(1) == ''
 endfunction
 
-function! xolox#misc#buffer#prepare(bufname)
-  let bufname = '[' . a:bufname . ']'
-  let buffers = tabpagebuflist()
-  call map(buffers, 'fnamemodify(bufname(v:val), ":t:r")')
-  let idx = index(buffers, bufname)
-  if idx >= 0
-    execute (idx + 1) . 'wincmd w'
-  elseif !(xolox#misc#buffer#is_empty() || expand('%:t') == bufname)
+function! xolox#misc#buffer#prepare(...) " {{{1
+  " Open a special buffer (with generated contents, not directly edited by the user).
+  if a:0 == 1 && type(a:1) == type('')
+    " Backwards compatibility with old interface.
+    let options = {'name': a:1, 'path': a:1}
+  elseif type(a:1) == type({})
+    let options = a:1
+  else
+    throw "Invalid arguments"
+  endif
+  let winnr = 1
+  let found = 0
+  for bufnr in tabpagebuflist()
+    if xolox#misc#path#equals(options['path'], bufname(bufnr))
+      execute winnr . 'wincmd w'
+      let found = 1
+      break
+    else
+      let winnr += 1
+    endif
+  endfor
+  if !(found || xolox#misc#buffer#is_empty())
     vsplit
   endif
-  silent execute 'edit' fnameescape(bufname)
+  silent execute 'edit' fnameescape(options['path'])
   lcd " clear working directory
   setlocal buftype=nofile bufhidden=hide noswapfile
-  let &l:statusline = bufname
+  let &l:statusline = '[' . options['name'] . ']'
   call xolox#misc#buffer#unlock()
   silent %delete
 endfunction
 
-function! xolox#misc#buffer#lock()
+function! xolox#misc#buffer#lock() " {{{1
   " Lock a special buffer so it can no longer be edited.
   setlocal readonly nomodifiable nomodified
 endfunction
 
-function! xolox#misc#buffer#unlock()
+function! xolox#misc#buffer#unlock() " {{{1
   " Unlock a special buffer so that its content can be updated.
   setlocal noreadonly modifiable
 endfunction
diff --git a/autoload/xolox/misc/compat.vim b/autoload/xolox/misc/compat.vim
new file mode 100644
index 0000000..83d00a0
--- /dev/null
+++ b/autoload/xolox/misc/compat.vim
@@ -0,0 +1,23 @@
+" Vim auto-load script
+" Author: Peter Odding <peter@peterodding.com>
+" Last Change: April 20, 2013
+" URL: http://peterodding.com/code/vim/misc/
+
+" The following integer will be bumped whenever a change in the miscellaneous
+" scripts breaks backwards compatibility. This enables my Vim plug-ins to fail
+" early when they detect an incompatible version, instead of breaking at the
+" worst possible moments :-).
+let g:xolox#misc#compat#version = 1
+
+" Remember the directory where the miscellaneous scripts are loaded from
+" so the user knows which plug-in to update if incompatibilities arise.
+let s:misc_directory = fnamemodify(expand('<sfile>'), ':p:h')
+
+function! xolox#misc#compat#check(plugin_name, required_version)
+  if a:required_version != g:xolox#misc#compat#version
+    let msg = "The %s plug-in requires version %i of the miscellaneous scripts, however version %i was loaded from %s!"
+    throw printf(msg, a:plugin_name, a:required_version, g:xolox#misc#compat#version, s:misc_directory)
+  endif
+endfunction
+
+" vim: ts=2 sw=2 et
diff --git a/autoload/xolox/misc/path.vim b/autoload/xolox/misc/path.vim
index efb6340..6f8fe44 100644
--- a/autoload/xolox/misc/path.vim
+++ b/autoload/xolox/misc/path.vim
@@ -1,9 +1,10 @@
 " Vim auto-load script
 " Author: Peter Odding <peter@peterodding.com>
-" Last Change: September 26, 2011
+" Last Change: April 18, 2013
 " URL: http://peterodding.com/code/vim/misc/
 
 let s:windows_compatible = has('win32') || has('win64')
+let s:mac_os_x_compatible = has('macunix')
 
 function! xolox#misc#path#which(...)
   let extensions = s:windows_compatible ? split($PATHEXT, ';') : ['']
@@ -129,7 +130,13 @@ endfunction
 " Encode a pathname so it can be used as a filename.
 
 function! xolox#misc#path#encode(path)
-  let mask = s:windows_compatible ? '[*|\\/:"<>?%]' : '[\\/%]'
+  if s:windows_compatible
+    let mask = '[*|\\/:"<>?%]'
+  elseif s:mac_os_x_compatible
+    let mask = '[\\/%:]'
+  else
+    let mask = '[\\/%]'
+  endif
   return substitute(a:path, mask, '\=printf("%%%x", char2nr(submatch(0)))', 'g')
 endfunction