Do not disable omnifunc when filetype completion is disabled

Allow users to still trigger Vim's omnifunc through C-Space when the
g:ycm_filetype_specific_completion_to_disable option is set for the current
filetype.

README.md

@@ -2077,7 +2077,8 @@ dictionary with keys being filetype strings (like `python`, `cpp` etc) and
 values being unimportant (the dictionary is used like a hash set, meaning that
 only the keys matter). The listed filetypes will be ignored by the YCM semantic
 completion engine, but the identifier-based completion engine will still trigger
-in files of those filetypes.
+in files of those filetypes. Vim's omnifunc can still be triggered with the
+`<C-Space>` key.
 
 Note that even if semantic completion is not turned off for a specific filetype,
 you will not get semantic completion if the semantic engine does not support

doc/youcompleteme.txt

@@ -2382,7 +2382,8 @@ dictionary with keys being filetype strings (like 'python', 'cpp' etc) and
 values being unimportant (the dictionary is used like a hash set, meaning that
 only the keys matter). The listed filetypes will be ignored by the YCM semantic
 completion engine, but the identifier-based completion engine will still
-trigger in files of those filetypes.
+trigger in files of those filetypes. Vim's omnifunc can still be triggered with
+the '<C-Space>' key.
 
 Note that even if semantic completion is not turned off for a specific
 filetype, you will not get semantic completion if the semantic engine does not

python/ycm/omni_completer.py

@@ -57,11 +57,22 @@ def ShouldUseNow( self, request_data ):
 
 
   def ShouldUseNowInner( self, request_data ):
-    if request_data.get( 'force_semantic', False ):
+    if request_data[ 'force_semantic' ]:
       return True
+    if self._CurrentFiletypeCompletionDisabled():
+      return False
     return super( OmniCompleter, self ).ShouldUseNowInner( request_data )
 
 
+  def _CurrentFiletypeCompletionDisabled( self ):
+    filetypes = vimsupport.CurrentFiletypes()
+    filetype_to_disable = self.user_options[
+      'filetype_specific_completion_to_disable' ]
+    if '*' in filetype_to_disable:
+      return True
+    return any( [ x in filetype_to_disable for x in filetypes ] )
+
+
   def ComputeCandidates( self, request_data ):
     if self.ShouldUseCache():
       return super( OmniCompleter, self ).ComputeCandidates( request_data )

python/ycm/tests/omni_completer_test.py

@@ -675,3 +675,55 @@ def Omnifunc( findstart, base ):
         'completion_start_column': 1
       } )
     )
+
+
+@YouCompleteMeInstance( {
+  'cache_omnifunc': 0,
+  'filetype_specific_completion_to_disable': { FILETYPE: 1 },
+  'semantic_triggers': TRIGGERS } )
+def OmniCompleter_GetCompletions_FiletypeDisabled_SemanticTrigger_test( ycm ):
+  def Omnifunc( findstart, base ):
+    if findstart:
+      return 5
+    return [ 'a', 'b', 'cdef' ]
+
+  current_buffer = VimBuffer( 'buffer',
+                              contents = [ 'test.' ],
+                              filetype = FILETYPE,
+                              omnifunc = Omnifunc )
+
+  with MockVimBuffers( [ current_buffer ], current_buffer, ( 1, 6 ) ):
+    ycm.SendCompletionRequest()
+    assert_that(
+      ycm.GetCompletionResponse(),
+      has_entries( {
+        'completions': empty(),
+        'completion_start_column': 6
+      } )
+    )
+
+
+@YouCompleteMeInstance( {
+  'cache_omnifunc': 0,
+  'filetype_specific_completion_to_disable': { FILETYPE: 1 },
+  'semantic_triggers': TRIGGERS } )
+def OmniCompleter_GetCompletions_FiletypeDisabled_ForceSemantic_test( ycm ):
+  def Omnifunc( findstart, base ):
+    if findstart:
+      return 5
+    return [ 'a', 'b', 'cdef' ]
+
+  current_buffer = VimBuffer( 'buffer',
+                              contents = [ 'test.' ],
+                              filetype = FILETYPE,
+                              omnifunc = Omnifunc )
+
+  with MockVimBuffers( [ current_buffer ], current_buffer, ( 1, 6 ) ):
+    ycm.SendCompletionRequest( force_semantic = True )
+    assert_that(
+      ycm.GetCompletionResponse(),
+      has_entries( {
+        'completions': ToBytesOnPY2( [ 'a', 'b', 'cdef' ] ),
+        'completion_start_column': 6
+      } )
+    )

python/ycm/youcompleteme.py

@@ -301,8 +301,7 @@ def RestartServer( self ):
   def SendCompletionRequest( self, force_semantic = False ):
     request_data = BuildRequestData()
     request_data[ 'force_semantic' ] = force_semantic
-    if ( not self.NativeFiletypeCompletionAvailable() and
-         self.CurrentFiletypeCompletionEnabled() ):
+    if not self.NativeFiletypeCompletionUsable():
       wrapped_request_data = RequestWrap( request_data )
       if self._omnicomp.ShouldUseNow( wrapped_request_data ):
         self._latest_completion_request = OmniCompletionRequest(
@@ -814,8 +813,7 @@ def CurrentFiletypeCompletionEnabled( self ):
       'filetype_specific_completion_to_disable' ]
     if '*' in filetype_to_disable:
       return False
-    else:
-      return not any( [ x in filetype_to_disable for x in filetypes ] )
+    return not any( [ x in filetype_to_disable for x in filetypes ] )
 
 
   def ShowDetailedDiagnostic( self ):