Zonble: KeyHandler // Prevents the user override model to store symbols.

Source/Modules/ControllerModules/KeyHandler.mm

@@ -201,10 +201,15 @@ static NSString *const kGraphVizOutputfile = @"/tmp/vChewing-visualization.dot";
 {
     size_t cursorIndex = [self _actualCandidateCursorIndex];
     string stringValue = [value UTF8String];
-    _builder->grid().fixNodeSelectedCandidate(cursorIndex, stringValue);
+    NodeAnchor selectedNode = _builder->grid().fixNodeSelectedCandidate(cursorIndex, stringValue);
     if (!Preferences.useSCPCTypingMode) { // 不要針對逐字選字模式啟用臨時半衰記憶模型。
+        // If the length of the readings and the characters do not match,
+        // it often means it is a special symbol and it should not be stored
+        // in the user override model.
+        if (selectedNode.spanningLength == [value count]) {
             _userOverrideModel->observe(_walkedNodes, cursorIndex, stringValue, [[NSDate date] timeIntervalSince1970]);
         }
+    }
     [self _walk];
 
     if (Preferences.selectPhraseAfterCursorAsCandidate &&

Source/Modules/LanguageParsers/Gramambular/Grid.h

@@ -40,11 +40,11 @@ namespace Taiyan {
             vector<NodeAnchor> nodesEndingAt(size_t inLocation);
             vector<NodeAnchor> nodesCrossingOrEndingAt(size_t inLocation);
 
-            // "Freeze" the node with the unigram that represents the selected canditate value.
+            // "Freeze" the node with the unigram that represents the selected candidate value.
             // After this, the node that contains the unigram will always be evaluated to that
             // unigram, while all other overlapping nodes will be reset to their initial state
             // (that is, if any of those nodes were "frozen" or fixed, they will be unfrozen.)
-            void fixNodeSelectedCandidate(size_t location, const string& value);
+            NodeAnchor fixNodeSelectedCandidate(size_t location, const string& value);
 
             // Similar to fixNodeSelectedCandidate, but instead of "freezing" the node, only
             // boost the unigram that represents the value with an overriding score. This
@@ -180,9 +180,10 @@ namespace Taiyan {
         }
 
         // For nodes found at the location, fix their currently-selected candidate using the supplied string value.
-        inline void Grid::fixNodeSelectedCandidate(size_t location, const string& value)
+        inline NodeAnchor Grid::fixNodeSelectedCandidate(size_t location, const string& value)
         {
             vector<NodeAnchor> nodes = nodesCrossingOrEndingAt(location);
+            NodeAnchor node;
             for (auto nodeAnchor : nodes) {
                 auto candidates = nodeAnchor.node->candidates();
 
@@ -192,10 +193,12 @@ namespace Taiyan {
                 for (size_t i = 0, c = candidates.size(); i < c; ++i) {
                     if (candidates[i].value == value) {
                         const_cast<Node*>(nodeAnchor.node)->selectCandidateAtIndex(i);
-                        break;
+                        node = nodeAnchor;
+                        break;;
                     }
                 }
             }
+            return node;
         }
 
         inline void Grid::overrideNodeScoreForSelectedCandidate(size_t location, const string& value, float overridingScore)

Source/Modules/LanguageParsers/Gramambular/Node.h

@@ -43,6 +43,7 @@ namespace Taiyan {
             
             const string& key() const;
             double score() const;
+            // double scoreForCandidate(string &candidate) const; // Prevents the override model to remember symbols with scode -X or lower.
             const KeyValuePair currentKeyValue() const;
             double highestUnigramScore() const;
             
@@ -190,6 +191,17 @@ namespace Taiyan {
             return m_score;
         }
 
+        // Prevents the override model to remember symbols with scode -X or lower.
+//        inline double Node::scoreForCandidate(string &candidate) const
+//        {
+//            for (auto unigram : m_unigrams) {
+//                if (unigram.keyValue.value == candidate) {
+//                    return unigram.score;
+//                }
+//            }
+//            return 0.0;
+//        }
+
         inline double Node::highestUnigramScore() const {
             if (m_unigrams.empty()) {
                 return 0.0;