Preserve current word in word completion if found elsewhere

If occurence count in the buffer if greater that one, do not
remove it from the matches.

src/input_handler.cc

@@ -776,11 +776,13 @@ public:
 
         String current_word{begin, end};
 
+        auto& word_db = get_word_db(buffer);
         std::unordered_set<String> matches;
-        auto bufmatches = get_word_db(buffer).find_prefix(prefix);
+        auto bufmatches = word_db.find_prefix(prefix);
         matches.insert(bufmatches.begin(), bufmatches.end());
 
-        matches.erase(current_word);
+        if (word_db.get_word_occurences(current_word) <= 1)
+            matches.erase(current_word);
 
         if (other_buffers)
         {

src/unit_tests.cc

@@ -80,6 +80,8 @@ void test_word_db()
     auto res = word_db.find_prefix("");
     std::sort(res.begin(), res.end());
     kak_assert(res == std::vector<String>{ "allo" COMMA "kanaky" COMMA "mutch" COMMA "tchaa" COMMA "tchou" });
+    kak_assert(word_db.get_word_occurences("tchou") == 3);
+    kak_assert(word_db.get_word_occurences("allo") == 1);
     buffer.erase(buffer.iterator_at({1, 6}), buffer.iterator_at({4, 0}));
     res = word_db.find_prefix("");
     std::sort(res.begin(), res.end());

src/word_db.cc

@@ -112,4 +112,12 @@ std::vector<String> WordDB::find_prefix(const String& prefix)
     return res;
 }
 
+int WordDB::get_word_occurences(const String& word) const
+{
+    auto it = m_words.find(word);
+    if (it != m_words.end())
+        return it->second;
+    return 0;
+}
+
 }

src/word_db.hh

@@ -18,6 +18,7 @@ public:
     WordDB(const Buffer& buffer);
 
     std::vector<String> find_prefix(const String& prefix);
+    int get_word_occurences(const String& word) const;
 
     using WordList = std::map<String, int>;
 private: