Merge #2703 'Clipboard: do not use &shell to invoke provider + cache owned clipboard'.

runtime/autoload/provider/clipboard.vim

@@ -1,46 +1,90 @@
 " The clipboard provider uses shell commands to communicate with the clipboard.
-" The provider function will only be registered if one of the supported
-" commands are available.
+" The provider function will only be registered if a supported command is
+" available.
 let s:copy = {}
 let s:paste = {}
 
+" When caching is enabled, store the jobid of the xclip/xsel process keeping
+" 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)
+  " 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
+    let self.owner = 0
+  endif
+endfunction
+
+let s:selections = { '*': s:selection, '+': copy(s:selection)}
+
 function! s:try_cmd(cmd, ...)
-  let out = a:0 ? systemlist(a:cmd, a:1, 1) : systemlist(a:cmd, [''], 1)
+  let argv = split(a:cmd, " ")
+  let out = a:0 ? systemlist(argv, a:1, 1) : systemlist(argv, [''], 1)
   if v:shell_error
+    echohl WarningMsg
     echo "clipboard: error: ".(len(out) ? out[0] : '')
-    return ''
+    echohl None
+    return 0
   endif
   return out
 endfunction
 
+let s:cache_enabled = 1
 if executable('pbcopy')
   let s:copy['+'] = 'pbcopy'
   let s:paste['+'] = 'pbpaste'
   let s:copy['*'] = s:copy['+']
   let s:paste['*'] = s:paste['+']
+  let s:cache_enabled = 0
 elseif executable('xclip')
-  let s:copy['+'] = 'xclip -i -selection clipboard'
+  let s:copy['+'] = 'xclip -quiet -i -selection clipboard'
   let s:paste['+'] = 'xclip -o -selection clipboard'
-  let s:copy['*'] = 'xclip -i -selection primary'
+  let s:copy['*'] = 'xclip -quiet -i -selection primary'
   let s:paste['*'] = 'xclip -o -selection primary'
 elseif executable('xsel')
-  let s:copy['+'] = 'xsel -i -b'
+  let s:copy['+'] = 'xsel --nodetach -i -b'
   let s:paste['+'] = 'xsel -o -b'
-  let s:copy['*'] = 'xsel -i -p'
+  let s:copy['*'] = 'xsel --nodetach -i -p'
   let s:paste['*'] = 'xsel -o -p'
 else
-  echom 'clipboard: No shell command for communicating with the clipboard found.'
+  echom 'clipboard: No clipboard tool available. See :help nvim-clipboard'
   finish
 endif
 
 let s:clipboard = {}
 
 function! s:clipboard.get(reg)
+  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)
-  call s:try_cmd(s:copy[a:reg], a:lines)
+  if s:cache_enabled == 0
+    call s:try_cmd(s:copy[a:reg], a:lines)
+    return 0
+  end
+
+  let selection = s:selections[a:reg]
+  if selection.owner > 0
+    " The previous provider instance should exit when the new one takes
+    " ownership, but kill it to be sure we don't fill up the job table.
+    call jobstop(selection.owner)
+  end
+  let selection.data = [a:lines, a:regtype]
+  let argv = split(s:copy[a:reg], " ")
+  let jobid = jobstart(argv, selection)
+  if jobid <= 0
+    echohl WarningMsg
+    echo "clipboard: error when invoking provider"
+    echohl None
+    return 0
+  endif
+  call jobsend(jobid, a:lines)
+  call jobclose(jobid, 'stdin')
+  let selection.owner = jobid
 endfunction
 
 function! provider#clipboard#Call(method, args)

src/nvim/ops.c

@@ -5291,6 +5291,9 @@ static yankreg_T *adjust_clipboard_name(int *name, bool quiet)
 
 static bool get_clipboard(int name, yankreg_T **target, bool quiet)
 {
+  // show message on error
+  bool errmsg = true;
+
   yankreg_T *reg = adjust_clipboard_name(&name, quiet);
   if (reg == NULL) {
     return false;
@@ -5304,6 +5307,10 @@ static bool get_clipboard(int name, yankreg_T **target, bool quiet)
   typval_T result = eval_call_provider("clipboard", "get", args);
 
   if (result.v_type != VAR_LIST) {
+    if (result.v_type == VAR_NUMBER && result.vval.v_number == 0) {
+      // failure has already been indicated by provider
+      errmsg = false;
+    }
     goto err;
   }
 
@@ -5389,7 +5396,9 @@ err:
   }
   reg->y_array = NULL;
   reg->y_size = 0;
-  EMSG("clipboard: provider returned invalid data");
+  if (errmsg) {
+    EMSG("clipboard: provider returned invalid data");
+  }
   *target = reg;
   return false;
 }