Editor: Propose full trigger match snippets

Snippets might insert a lot more text than just the completion item text
so don't hide a completion if the trigger is typed in completely. But do
not show completions when we type in a snippet with a trigger that can
be also interpreted as a keyword or ordinary completion item.

Change-Id: I25afe5f566e1c8f30621e2f82356c1c5f0af1311
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/texteditor/codeassist/genericproposalmodel.cpp

@@ -217,7 +217,8 @@ bool GenericProposalModel::isPerfectMatch(const QString &prefix) const
             if (proposalItem(i)->isKeyword())
                 return true;
 
-            hasFullMatch = true;
+            if (!proposalItem(i)->isSnippet())
+                hasFullMatch = true;
         }
     }