Ignore null nodes in Append_Location.

Author: reznikmm

source/ada/lsp-ada_declaration.adb

@@ -219,8 +219,8 @@ package body LSP.Ada_Declaration is
            (Self.Response,
             Self.Filter,
             Prev_Part);
-      elsif not Definition.Is_Null then
-         --  No previous part, return definition itself.
+      else
+         --  No previous part, return definition itself, if not null.
          Self.Parent.Context.Append_Location
            (Self.Response,
             Self.Filter,

source/ada/lsp-ada_definition.adb

@@ -248,14 +248,12 @@ package body LSP.Ada_Definition is
             Manual_Fallback := Laltools.Common.Find_Other_Part_Fallback
               (Definition, Trace);
 
-            if not Manual_Fallback.Is_Null then
-               --  We have found a result using the imprecise heuristics.
-               --  We'll warn the user and send the result.
-               Self.Parent.Context.Append_Location
-                 (Self.Response,
-                  Self.Filter,
-                  Manual_Fallback);
-            end if;
+            --  If we have found a result using the imprecise heuristics then
+            --  append it.
+            Self.Parent.Context.Append_Location
+              (Self.Response,
+               Self.Filter,
+               Manual_Fallback);
          else
             Self.Parent.Context.Append_Location
               (Self.Response,

source/ada/lsp-ada_handlers-locations.adb

@@ -47,7 +47,7 @@ package body LSP.Ada_Handlers.Locations is
       Node   : Libadalang.Analysis.Ada_Node'Class;
       Kinds  : LSP.Structures.AlsReferenceKind_Set := LSP.Constants.Empty) is
    begin
-      if not LSP.Utils.Is_Synthetic (Node) then
+      if not Node.Is_Null and then not LSP.Utils.Is_Synthetic (Node) then
          declare
             Value : constant LSP.Structures.Location :=
               To_LSP_Location (Self, Node, Kinds);

source/ada/lsp-ada_handlers-locations.ads

@@ -80,6 +80,7 @@ package LSP.Ada_Handlers.Locations is
       Kinds  : LSP.Structures.AlsReferenceKind_Set := LSP.Constants.Empty);
    --  Append given Node location to the Result.
    --  Do nothing if the item inside of an synthetic file (like __standard).
+   --  Null Node is ignored.
 
    procedure Append_Location
      (Result   : in out LSP.Structures.DocumentHighlight_Vector;