provider/clipboard.vim: Handle missing g:clipboard keys

runtime/autoload/provider/clipboard.vim

@@ -8,7 +8,7 @@ let s:paste = {}
 " ownership of the selection, so we know how long the cache is valid.
 let s:selection = { 'owner': 0, 'data': [] }
 
-function! s:selection.on_exit(jobid, data, event)
+function! s:selection.on_exit(jobid, data, event) abort
   " At this point this nvim instance might already have launched
   " a new provider instance. Don't drop ownership in this case.
   if self.owner == a:jobid
@@ -18,7 +18,7 @@ endfunction
 
 let s:selections = { '*': s:selection, '+': copy(s:selection)}
 
-function! s:try_cmd(cmd, ...)
+function! s:try_cmd(cmd, ...) abort
   let argv = split(a:cmd, " ")
   let out = a:0 ? systemlist(argv, a:1, 1) : systemlist(argv, [''], 1)
   if v:shell_error
@@ -34,7 +34,7 @@ function! s:try_cmd(cmd, ...)
 endfunction
 
 " Returns TRUE if `cmd` exits with success, else FALSE.
-function! s:cmd_ok(cmd)
+function! s:cmd_ok(cmd) abort
   call system(a:cmd)
   return v:shell_error == 0
 endfunction
@@ -48,10 +48,10 @@ endfunction
 
 function! provider#clipboard#Executable() abort
   if exists('g:clipboard')
-    let s:copy = g:clipboard.copy
-    let s:paste = g:clipboard.paste
-    let s:cache_enabled = g:clipboard.cache_enabled
-    return g:clipboard.name
+    let s:copy = get(g:clipboard, 'copy', { '+': v:null, '*': v:null })
+    let s:paste = get(g:clipboard, 'paste', { '+': v:null, '*': v:null })
+    let s:cache_enabled = get(g:clipboard, 'cache_enabled', 1)
+    return get(g:clipboard, 'name', 'g:clipboard')
   elseif has('mac') && executable('pbcopy')
     let s:copy['+'] = 'pbcopy'
     let s:paste['+'] = 'pbpaste'
@@ -107,14 +107,14 @@ endif
 
 let s:clipboard = {}
 
-function! s:clipboard.get(reg)
+function! s:clipboard.get(reg) abort
   if s:selections[a:reg].owner > 0
     return s:selections[a:reg].data
   end
   return s:try_cmd(s:paste[a:reg])
 endfunction
 
-function! s:clipboard.set(lines, regtype, reg)
+function! s:clipboard.set(lines, regtype, reg) abort
   if a:reg == '"'
     call s:clipboard.set(a:lines,a:regtype,'+')
     if s:copy['*'] != s:copy['+']
@@ -149,6 +149,6 @@ function! s:clipboard.set(lines, regtype, reg)
   let selection.owner = jobid
 endfunction
 
-function! provider#clipboard#Call(method, args)
+function! provider#clipboard#Call(method, args) abort
   return call(s:clipboard[a:method],a:args,s:clipboard)
 endfunction

runtime/doc/provider.txt

@@ -116,48 +116,48 @@ To use the RVM "system" Ruby installation: >
 ==============================================================================
 Clipboard integration 			      *provider-clipboard* *clipboard*
 
-Nvim has no direct connection to the system clipboard. Instead it is
-accessible through a |provider| which transparently uses shell commands for
-communicating with the clipboard.
+Nvim has no direct connection to the system clipboard. Instead it depends on
+a |provider| which transparently uses shell commands to communicate with the
+system clipboard or any other clipboard "backend".
 
-Clipboard access is implicitly enabled if any of the following clipboard tools
-are found in your `$PATH`.
+To ALWAYS use the clipboard for ALL operations (instead of interacting with
+the '+' and/or '*' registers explicitly): >
 
+    set clipboard+=unnamedplus
+<
+See 'clipboard' for details and options.
+
+							      *clipboard-tool*
+The presence of a working clipboard tool implicitly enables the '+' and '*'
+registers. Nvim looks for these clipboard tools, in order of priority:
+
+  - |g:clipboard|
+  - pbcopy/pbpaste (macOS)
   - xclip
   - xsel (newer alternative to xclip)
-  - pbcopy/pbpaste (macOS)
   - lemonade (for SSH) https://github.com/pocke/lemonade
   - doitclient (for SSH) http://www.chiark.greenend.org.uk/~sgtatham/doit/
+  - win32yank (Windows)
+  - tmux (if $TMUX is set)
 
-If you would like to configure the provider: >
+								 *g:clipboard*
+To configure a custom clipboard tool, set `g:clipboard` to a dictionary: >
     let g:clipboard = {
           \   'name': 'myClipboard',
           \   'copy': {
-          \      '+': 'copyCommand',
-          \      '*': 'copyCommand',
+          \      '+': 'tmux load-buffer -',
+          \      '*': 'tmux load-buffer -',
           \    },
           \   'paste': {
-          \      '+': 'pasteCommand',
-          \      '*': 'pasteCommand',
+          \      '+': 'tmux save-buffer -',
+          \      '*': 'tmux save-buffer -',
           \   },
           \   'cache_enabled': 1,
           \ }
 
-If the cache is enabled, then when a selection is copied and the copy command
-is executed, neovim will cache this selection until the copy command process
-dies. Then, when pasting, if the copy command process has not died, the cached
-selection is returned instead of executing the paste command.
-
-The presence of a suitable clipboard tool implicitly enables the '+' and '*'
-registers.
-
-If you want to ALWAYS use the clipboard for ALL operations (as opposed
-to interacting with the '+' and/or '*' registers explicitly), set the
-following option:
->
-    set clipboard+=unnamedplus
-<
-See 'clipboard' for details and more options.
+If `cache_enabled` is |TRUE| then when a selection is copied, Nvim will cache
+the selection until the copy command process dies. When pasting, if the copy
+process has not died, the cached selection is applied.
 
 ==============================================================================
 X11 selection mechanism			      *clipboard-x11* *x11-selection*