Adds method resolveFirstCopy to collections

Using the copy whenever it is necessary to avoid memory leak.

src/collection/backend/in_memory-per_process.cc

@@ -123,6 +123,17 @@ std::string* InMemoryPerProcess::resolveFirst(const std::string& var) {
 }
 
 
+std::string InMemoryPerProcess::resolveFirstCopy(const std::string& var) {
+    auto range = equal_range(var);
+
+    for (auto it = range.first; it != range.second; ++it) {
+        return it->second;
+    }
+
+    return "";
+}
+
+
 }  // namespace backend
 }  // namespace collection
 }  // namespace modsecurity

src/collection/backend/in_memory-per_process.h

@@ -83,6 +83,7 @@ class InMemoryPerProcess :
     void del(const std::string& key) override;
 
     std::string* resolveFirst(const std::string& var) override;
+    std::string resolveFirstCopy(const std::string& var) override;
 
     void resolveSingleMatch(const std::string& var,
         std::vector<const Variable *> *l) override;

src/collection/backend/lmdb.cc

@@ -155,6 +155,47 @@ void LMDB::lmdb_debug(int rc, std::string op, std::string scope) {
 #endif
 }
 
+
+std::string LMDB::resolveFirstCopy(const std::string& var) {
+    int rc;
+    MDB_val mdb_key;
+    MDB_val mdb_value;
+    MDB_val mdb_value_ret;
+    std::string ret;
+    MDB_txn *txn = NULL;
+    MDB_dbi dbi;
+
+    string2val(var, &mdb_key);
+
+    rc = mdb_txn_begin(m_env, NULL, 0, &txn);
+    lmdb_debug(rc, "txn", "resolveFirst");
+    if (rc != 0) {
+        goto end_txn;
+    }
+    rc = mdb_dbi_open(txn, NULL, MDB_CREATE | MDB_DUPSORT, &dbi);
+    lmdb_debug(rc, "dbi", "resolveFirst");
+    if (rc != 0) {
+        goto end_dbi;
+    }
+    rc = mdb_get(txn, dbi, &mdb_key, &mdb_value_ret);
+    lmdb_debug(rc, "get", "resolveFirst");
+    if (rc != 0) {
+        goto end_get;
+    }
+
+    ret.assign(
+        reinterpret_cast<char *>(mdb_value_ret.mv_data),
+        mdb_value_ret.mv_size);
+
+end_get:
+    mdb_dbi_close(m_env, dbi);
+end_dbi:
+    mdb_txn_abort(txn);
+end_txn:
+    return ret;
+}
+
+
 std::string* LMDB::resolveFirst(const std::string& var) {
     int rc;
     MDB_val mdb_key;

src/collection/backend/lmdb.h

@@ -57,6 +57,7 @@ class LMDB :
     void del(const std::string& key) override;
 
     std::string* resolveFirst(const std::string& var) override;
+    std::string resolveFirstCopy(const std::string& var) override;
 
     void resolveSingleMatch(const std::string& var,
         std::vector<const Variable *> *l) override;

src/collection/collections.cc

@@ -183,6 +183,68 @@ std::string* Collections::resolveFirst(const std::string& collectionName,
 }
 
 
+std::string Collections::resolveFirstCopy(const std::string& var) {
+    std::string transientVar = m_transient->resolveFirstCopy(var);
+
+    if (transientVar.empty() == false) {
+        return transientVar;
+    }
+
+    for (auto &a : *this) {
+        std::string res = a.second->resolveFirstCopy(toupper(a.first) +
+            ":" + var);
+        if (res.empty() == false) {
+            return res;
+        }
+    }
+
+    return "";
+}
+
+
+std::string Collections::resolveFirstCopy(const std::string& collectionName,
+        const std::string& var) {
+        if (tolower(collectionName) == "ip"
+            && !m_ip_collection_key.empty()) {
+            return m_ip_collection->resolveFirstCopy(toupper(collectionName)
+                    + ":" + var, m_ip_collection_key);
+        }
+
+        if (tolower(collectionName) == "global"
+            && !m_global_collection_key.empty()) {
+            return m_global_collection->resolveFirstCopy(
+                toupper(collectionName) + ":" + var,
+                m_global_collection_key);
+        }
+
+        if (tolower(collectionName) == "resource"
+            && !m_resource_collection_key.empty()) {
+            return m_resource_collection->resolveFirstCopy(
+                toupper(collectionName) + ":" + var,
+                m_resource_collection_key);
+        }
+
+        if (tolower(collectionName) == "session"
+            && !m_session_collection_key.empty()) {
+            return m_session_collection->resolveFirstCopy(
+                toupper(collectionName) + ":" + var,
+                m_session_collection_key);
+        }
+
+        for (auto &a : *this) {
+            if (tolower(a.first) == tolower(collectionName)) {
+                std::string res = a.second->resolveFirstCopy(toupper(a.first)
+                    + ":" + var);
+                if (res.empty() == false) {
+                    return res;
+                }
+            }
+        }
+
+        return "";
+}
+
+
 void Collections::resolveSingleMatch(const std::string& var,
     std::vector<const Variable *> *l) {