Recompute starting column on auto-wrapping

When auto-wrapping is enabled, Vim wraps the current line after the
completion request is sent but before calling the completefunc. The
starting column returned by the server is invalid in that case and must
be recomputed.

autoload/youcompleteme.vim

@@ -23,11 +23,9 @@ set cpo&vim
 let s:script_folder_path = escape( expand( '<sfile>:p:h' ), '\' )
 let s:force_semantic = 0
 let s:completion_stopped = 0
-let s:default_completion = {
-      \   'start_column': -1,
-      \   'candidates': []
-      \ }
-let s:completion = s:default_completion
+" These two variables are initialized in youcompleteme#Enable.
+let s:default_completion = {}
+let s:completion = {}
 let s:previous_allowed_buffer_number = 0
 let s:pollers = {
       \   'completion': {
@@ -147,6 +145,9 @@ function! youcompleteme#Enable()
   let s:pollers.server_ready.id = timer_start(
         \ s:pollers.server_ready.wait_milliseconds,
         \ function( 's:PollServerReady' ) )
+
+  let s:default_completion = s:Pyeval( 'vimsupport.NO_COMPLETIONS' )
+  let s:completion = s:default_completion
 endfunction
 
 
@@ -811,11 +812,7 @@ function! s:PollCompletion( ... )
     return
   endif
 
-  let response = s:Pyeval( 'ycm_state.GetCompletionResponse()' )
-  let s:completion = {
-        \   'start_column': response.completion_start_column,
-        \   'candidates': response.completions
-        \ }
+  let s:completion = s:Pyeval( 'ycm_state.GetCompletionResponse()' )
   call s:Complete()
 endfunction
 
@@ -824,16 +821,17 @@ function! s:Complete()
   " Do not call user's completion function if the start column is after the
   " current column or if there are no candidates. Close the completion menu
   " instead. This avoids keeping the user in completion mode.
-  if s:completion.start_column > col( '.' ) || empty( s:completion.candidates )
+  if s:completion.completion_start_column > s:completion.column ||
+        \ empty( s:completion.completions )
     call s:CloseCompletionMenu()
   else
     " <c-x><c-u> invokes the user's completion function (which we have set to
     " youcompleteme#CompleteFunc), and <c-p> tells Vim to select the previous
-    " completion candidate. This is necessary because by default, Vim selects the
-    " first candidate when completion is invoked, and selecting a candidate
-    " automatically replaces the current text with it. Calling <c-p> forces Vim to
-    " deselect the first candidate and in turn preserve the user's current text
-    " until he explicitly chooses to replace it with a completion.
+    " completion candidate. This is necessary because by default, Vim selects
+    " the first candidate when completion is invoked, and selecting a candidate
+    " automatically replaces the current text with it. Calling <c-p> forces Vim
+    " to deselect the first candidate and in turn preserve the user's current
+    " text until he explicitly chooses to replace it with a completion.
     call s:SendKeys( "\<C-X>\<C-U>\<C-P>" )
   endif
 endfunction
@@ -841,9 +839,25 @@ endfunction
 
 function! youcompleteme#CompleteFunc( findstart, base )
   if a:findstart
-    return s:completion.start_column - 1
+    " When auto-wrapping is enabled, Vim wraps the current line after the
+    " completion request is sent but before calling this function. The starting
+    " column returned by the server is invalid in that case and must be
+    " recomputed.
+    if s:completion.line != line( '.' )
+      " Given
+      "   scb: column where the completion starts before auto-wrapping
+      "   cb: cursor column before auto-wrapping
+      "   sca: column where the completion starts after auto-wrapping
+      "   ca: cursor column after auto-wrapping
+      " we have
+      "   ca - sca = cb - scb
+      "   sca = scb + ca - cb
+      let s:completion.completion_start_column +=
+            \ col( '.' ) - s:completion.column
     endif
-  return s:completion.candidates
+    return s:completion.completion_start_column - 1
+  endif
+  return s:completion.completions
 endfunction
 
 

python/ycm/client/completion_request.py

@@ -28,6 +28,7 @@ from ycmd.utils import ToUnicode
 from ycm.client.base_request import ( BaseRequest, DisplayServerException,
                                       MakeServerException )
 from ycm import vimsupport
+from ycm.vimsupport import NO_COMPLETIONS
 
 _logger = logging.getLogger( __name__ )
 
@@ -56,12 +57,12 @@ class CompletionRequest( BaseRequest ):
 
   def RawResponse( self ):
     if not self._response_future:
-      return { 'completions': [], 'completion_start_column': -1 }
+      return NO_COMPLETIONS
 
     response = self.HandleFuture( self._response_future,
                                   truncate_message = True )
     if not response:
-      return { 'completions': [], 'completion_start_column': -1 }
+      return NO_COMPLETIONS
 
     # Vim may not be able to convert the 'errors' entry to its internal format
     # so we remove it from the response.
@@ -71,6 +72,8 @@ class CompletionRequest( BaseRequest ):
       _logger.error( exception )
       DisplayServerException( exception, truncate_message = True )
 
+    response[ 'line' ] = self.request_data[ 'line_num' ]
+    response[ 'column' ] = self.request_data[ 'column_num' ]
     return response
 
 

python/ycm/client/omni_completion_request.py

@@ -41,15 +41,19 @@ class OmniCompletionRequest( CompletionRequest ):
 
   def RawResponse( self ):
     return {
-      'completions': _ConvertVimDatasToCompletionDatas( self._results ),
-      'completion_start_column': self.request_data[ 'start_column' ]
+      'line': self.request_data[ 'line_num' ],
+      'column': self.request_data[ 'column_num' ],
+      'completion_start_column': self.request_data[ 'start_column' ],
+      'completions': _ConvertVimDatasToCompletionDatas( self._results )
     }
 
 
   def Response( self ):
     return {
-      'completions': self._results,
-      'completion_start_column': self.request_data[ 'start_column' ]
+      'line': self.request_data[ 'line_num' ],
+      'column': self.request_data[ 'column_num' ],
+      'completion_start_column': self.request_data[ 'start_column' ],
+      'completions': self._results
     }
 
 

python/ycm/tests/client/omni_completion_request_tests.py

@@ -34,6 +34,8 @@ def BuildOmnicompletionRequest( results, start_column = 1 ):
   omni_completer.ComputeCandidates = MagicMock( return_value = results )
 
   request_data = {
+    'line_num': 1,
+    'column_num': 1,
     'start_column': start_column
   }
   request = OmniCompletionRequest( omni_completer, request_data )
@@ -53,8 +55,10 @@ def Response_FromOmniCompleter_test():
   request = BuildOmnicompletionRequest( results )
 
   eq_( request.Response(), {
-    'completions': results,
-    'completion_start_column': 1
+    'line': 1,
+    'column': 1,
+    'completion_start_column': 1,
+    'completions': results
   } )
 
 

python/ycm/vimsupport.py

@@ -59,6 +59,13 @@ SIGN_ID_FOR_BUFFER = defaultdict( lambda: SIGN_BUFFER_ID_INITIAL_VALUE )
 SIGN_PLACE_REGEX = re.compile(
   r"^.*=(?P<line>\d+).*=(?P<id>\d+).*=(?P<name>Ycm\w+)$" )
 
+NO_COMPLETIONS = {
+  'line': -1,
+  'column': -1,
+  'completion_start_column': -1,
+  'completions': []
+}
+
 
 def CurrentLineAndColumn():
   """Returns the 0-based current line and 0-based current column."""