Fix clang-tidy check readability-implicit-bool-cast.

27 files changed, 100 insertions, 100 deletions

diff --git a/src/resources/db/avatardb.cpp b/src/resources/db/avatardb.cpp
index eddf08b29..86c2ff5aa 100644
--- a/src/resources/db/avatardb.cpp
+++ b/src/resources/db/avatardb.cpp
@@ -59,7 +59,7 @@ void AvatarDB::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "avatars"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "avatars"))
     {
         logger->log("Avatars Database: Error while loading %s!",
             fileName.c_str());
@@ -85,7 +85,7 @@ void AvatarDB::loadXmlFile(const std::string &fileName,
         BeingInfo *currentInfo = nullptr;
         if (mAvatarInfos.find(id) != mAvatarInfos.end())
             currentInfo = mAvatarInfos[id];
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setName(XML::langProperty(
diff --git a/src/resources/db/chardb.cpp b/src/resources/db/chardb.cpp
index b0984a56f..fe87ea157 100644
--- a/src/resources/db/chardb.cpp
+++ b/src/resources/db/chardb.cpp
@@ -54,7 +54,7 @@ void CharDB::load()
         SkipError_false);
     XmlNodeConstPtrConst root = doc->rootNode();
 
-    if (!root || !xmlNameEqual(root, "chars"))
+    if ((root == nullptr) || !xmlNameEqual(root, "chars"))
     {
         logger->log("CharDB: Failed to parse %s.",
             paths.getStringValue("charCreationFile").c_str());
@@ -113,9 +113,9 @@ void CharDB::loadMinMax(XmlNodeConstPtr node,
                         unsigned *restrict const min,
                         unsigned *restrict const max)
 {
-    if (min)
+    if (min != nullptr)
         *min = XML::getProperty(node, "min", 1);
-    if (max)
+    if (max != nullptr)
         *max = XML::getProperty(node, "max", 10);
 }
 
diff --git a/src/resources/db/colordb.cpp b/src/resources/db/colordb.cpp
index cf377eca1..15e66bb5b 100644
--- a/src/resources/db/colordb.cpp
+++ b/src/resources/db/colordb.cpp
@@ -83,7 +83,7 @@ void ColorDB::loadHair(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst root = doc->rootNode();
 
-    if (!root || !xmlNameEqual(root, "colors"))
+    if ((root == nullptr) || !xmlNameEqual(root, "colors"))
     {
         logger->log("ColorDB: Failed to find hair colors file.");
         if (colors.find(ItemColor_zero) == colors.end())
@@ -128,7 +128,7 @@ void ColorDB::loadColorLists(const std::string &fileName,
         UseVirtFs_true,
         skipError);
     XmlNodeConstPtrConst root = doc->rootNode();
-    if (!root)
+    if (root == nullptr)
     {
         delete doc;
         return;
diff --git a/src/resources/db/commandsdb.cpp b/src/resources/db/commandsdb.cpp
index 115046b1d..eec3eb7ce 100644
--- a/src/resources/db/commandsdb.cpp
+++ b/src/resources/db/commandsdb.cpp
@@ -64,7 +64,7 @@ void CommandsDB::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "commands"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "commands"))
     {
         logger->log("Commands Database: Error while loading %s!",
             fileName.c_str());
@@ -121,7 +121,7 @@ void CommandsDB::loadXmlFile(const std::string &fileName,
 
         TextCommand *cmd = nullptr;
 #ifdef TMWA_SUPPORT
-        if (skill1)
+        if (skill1 != 0)
         {
             cmd = new TextCommand(id,
                 name,
diff --git a/src/resources/db/deaddb.cpp b/src/resources/db/deaddb.cpp
index 53a0f6e0f..bcca023eb 100644
--- a/src/resources/db/deaddb.cpp
+++ b/src/resources/db/deaddb.cpp
@@ -54,7 +54,7 @@ void DeadDB::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst root = doc->rootNode();
 
-    if (!root || !xmlNameEqual(root, "messages"))
+    if ((root == nullptr) || !xmlNameEqual(root, "messages"))
     {
         logger->log("DeadDB: Failed to parse %s.",
             paths.getStringValue("deadMessagesFile").c_str());
@@ -75,9 +75,9 @@ void DeadDB::loadXmlFile(const std::string &fileName,
         {
             XmlChar *const data = reinterpret_cast<XmlChar*>(
                 XmlNodeGetContent(node));
-            if (!data)
+            if (data == nullptr)
                 continue;
-            if (!*data)
+            if (*data == 0)
             {
                 XmlFree(data);
                 continue;
@@ -99,7 +99,7 @@ void DeadDB::unload()
 std::string DeadDB::getRandomString()
 {
     const size_t sz = mMessages.size();
-    if (!sz)
+    if (sz == 0u)
         return std::string();
     return translator->getStr(mMessages[rand() % sz]);
 }
diff --git a/src/resources/db/elementaldb.cpp b/src/resources/db/elementaldb.cpp
index 2a626a10e..8701081a3 100644
--- a/src/resources/db/elementaldb.cpp
+++ b/src/resources/db/elementaldb.cpp
@@ -57,7 +57,7 @@ void ElementalDb::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtr rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "elementals"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "elementals"))
     {
         logger->log("Elemental Database: Error while loading %s!",
             paths.getStringValue("elementalsFile").c_str());
@@ -89,7 +89,7 @@ void ElementalDb::loadXmlFile(const std::string &fileName,
             logger->log("ElementalDb: Redefinition of elemental ID %d", id);
             currentInfo = mElementalInfos[fromInt(id + offset, BeingTypeId)];
         }
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setBlockType(BlockType::NONE);
@@ -107,7 +107,7 @@ void ElementalDb::loadXmlFile(const std::string &fileName,
         currentInfo->setColorsList(XML::getProperty(elementalNode,
             "colors", ""));
 
-        if (currentInfo->getMaxHP())
+        if (currentInfo->getMaxHP() != 0)
             currentInfo->setStaticMaxHP(true);
 
         SpriteDisplay display;
diff --git a/src/resources/db/emotedb.cpp b/src/resources/db/emotedb.cpp
index 7d9e47e8b..085f81abe 100644
--- a/src/resources/db/emotedb.cpp
+++ b/src/resources/db/emotedb.cpp
@@ -75,7 +75,7 @@ void EmoteDB::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodePtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "emotes"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "emotes"))
     {
         logger->log("Emote Database: Error while loading %s!",
             fileName.c_str());
@@ -113,7 +113,7 @@ void EmoteDB::loadXmlFile(const std::string &fileName,
             currentInfo = mEmoteInfos[id];
         else
             currentInfo = new EmoteInfo;
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             continue;
         currentInfo->time = XML::getProperty(emoteNode, "time", 500);
         currentInfo->effectId = XML::getProperty(emoteNode, "effect", -1);
@@ -152,7 +152,7 @@ void EmoteDB::loadSpecialXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodePtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "emotes"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "emotes"))
     {
         logger->log1("Emote Database: Error while loading"
                      " manaplus_emotes.xml!");
@@ -186,7 +186,7 @@ void EmoteDB::loadSpecialXmlFile(const std::string &fileName,
         EmoteInfo *currentInfo = nullptr;
         if (mEmoteInfos.find(id) != mEmoteInfos.end())
             currentInfo = mEmoteInfos[id];
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new EmoteInfo;
         currentInfo->time = XML::getProperty(emoteNode, "time", 500);
         currentInfo->effectId = XML::getProperty(emoteNode, "effect", -1);
@@ -226,7 +226,7 @@ void EmoteDB::unload()
 {
     FOR_EACH (EmoteInfos::const_iterator, i, mEmoteInfos)
     {
-        if (i->second)
+        if (i->second != nullptr)
         {
             std::list<EmoteSprite*> &sprites = i->second->sprites;
             while (!sprites.empty())
@@ -295,7 +295,7 @@ const EmoteInfo *EmoteDB::get2(int id, const bool allowNull)
 const EmoteSprite *EmoteDB::getSprite(const int id, const bool allowNull)
 {
     const EmoteInfo *const info = get(id, allowNull);
-    if (!info)
+    if (info == nullptr)
         return nullptr;
 
     return info->sprites.front();
diff --git a/src/resources/db/homunculusdb.cpp b/src/resources/db/homunculusdb.cpp
index cf627dc01..3fdced887 100644
--- a/src/resources/db/homunculusdb.cpp
+++ b/src/resources/db/homunculusdb.cpp
@@ -58,7 +58,7 @@ void HomunculusDB::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtr rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "homunculuses"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "homunculuses"))
     {
         logger->log("Homunculus Database: Error while loading %s!",
             paths.getStringValue("homunculusesFile").c_str());
@@ -90,7 +90,7 @@ void HomunculusDB::loadXmlFile(const std::string &fileName,
             logger->log("HomunculusDB: Redefinition of homunculus ID %d", id);
             currentInfo = mHomunculusInfos[fromInt(id + offset, BeingTypeId)];
         }
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setBlockType(BlockType::NONE);
@@ -114,7 +114,7 @@ void HomunculusDB::loadXmlFile(const std::string &fileName,
         currentInfo->setColorsList(XML::getProperty(homunculusNode,
             "colors", ""));
 
-        if (currentInfo->getMaxHP())
+        if (currentInfo->getMaxHP() != 0)
             currentInfo->setStaticMaxHP(true);
 
         SpriteDisplay display;
diff --git a/src/resources/db/horsedb.cpp b/src/resources/db/horsedb.cpp
index a6b395d3f..961fbca32 100644
--- a/src/resources/db/horsedb.cpp
+++ b/src/resources/db/horsedb.cpp
@@ -153,7 +153,7 @@ void HorseDB::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodePtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "horses"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "horses"))
     {
         logger->log("Horse Database: Error while loading %s!",
             fileName.c_str());
@@ -189,7 +189,7 @@ void HorseDB::loadXmlFile(const std::string &fileName,
         else
             currentInfo = new HorseInfo;
 
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             continue;
         for_each_xml_child_node(spriteNode, horseNode)
         {
diff --git a/src/resources/db/itemdb.cpp b/src/resources/db/itemdb.cpp
index 4bd68c42e..6efe6086f 100644
--- a/src/resources/db/itemdb.cpp
+++ b/src/resources/db/itemdb.cpp
@@ -129,7 +129,7 @@ static void readFields(std::string &effect,
                        XmlNodeConstPtr node,
                        const ItemFieldDb::FieldInfos &fields)
 {
-    if (!translator)
+    if (translator == nullptr)
         return;
 
     FOR_EACH (ItemFieldDb::FieldInfos::const_iterator, it, fields)
@@ -249,7 +249,7 @@ void ItemDB::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "items"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "items"))
     {
         logger->log("ItemDB: Error while loading %s!", fileName.c_str());
         mLoaded = true;
@@ -287,7 +287,7 @@ void ItemDB::loadXmlFile(const std::string &fileName,
             logger->log("ItemDB: Redefinition of item ID %d", id);
             itemInfo = mItemInfos[id];
         }
-        if (!itemInfo)
+        if (itemInfo == nullptr)
             itemInfo = new ItemInfo;
 
         const std::string typeStr = XML::getProperty(node, "type", "");
@@ -375,7 +375,7 @@ void ItemDB::loadXmlFile(const std::string &fileName,
         }
 
         itemInfo->setId(id);
-        if (name.empty() && inheritItemInfo)
+        if (name.empty() && (inheritItemInfo != nullptr))
             name = inheritItemInfo->getName();
         // TRANSLATORS: item info name
         itemInfo->setName(name.empty() ? _("unnamed") : name);
@@ -389,12 +389,12 @@ void ItemDB::loadXmlFile(const std::string &fileName,
             itemInfo->setNameEn(nameEn);
         }
 
-        if (description.empty() && inheritItemInfo)
+        if (description.empty() && (inheritItemInfo != nullptr))
             description = inheritItemInfo->getDescription();
         itemInfo->setDescription(description);
         if (typeStr.empty())
         {
-            if (inheritItemInfo)
+            if (inheritItemInfo != nullptr)
                 itemInfo->setType(inheritItemInfo->getType());
             else
                 itemInfo->setType(itemTypeFromString("other"));
@@ -404,12 +404,12 @@ void ItemDB::loadXmlFile(const std::string &fileName,
             itemInfo->setType(itemTypeFromString(typeStr));
         }
         itemInfo->setType(itemTypeFromString(typeStr));
-        if (useButton.empty() && inheritItemInfo)
+        if (useButton.empty() && (inheritItemInfo != nullptr))
             useButton = inheritItemInfo->getUseButton();
         if (useButton.empty())
             useButton = useButtonFromItemType(itemInfo->getType());
         itemInfo->setUseButton(useButton);
-        if (useButton2.empty() && inheritItemInfo)
+        if (useButton2.empty() && (inheritItemInfo != nullptr))
             useButton2 = inheritItemInfo->getUseButton();
         if (useButton2.empty())
             useButton2 = useButton2FromItemType(itemInfo->getType());
@@ -419,7 +419,7 @@ void ItemDB::loadXmlFile(const std::string &fileName,
             node, "sellProtected", false));
         if (cardColor != -1)
             itemInfo->setCardColor(fromInt(cardColor, ItemColor));
-        else if (inheritItemInfo)
+        else if (inheritItemInfo != nullptr)
             itemInfo->setCardColor(inheritItemInfo->getCardColor());
 
         switch (itemInfo->getType())
@@ -462,46 +462,46 @@ void ItemDB::loadXmlFile(const std::string &fileName,
             }
         }
 
-        if (!view && inheritItemInfo)
+        if ((view == 0) && (inheritItemInfo != nullptr))
             view = inheritItemInfo->getView();
         itemInfo->setView(view);
-        if (!weight && inheritItemInfo)
+        if ((weight == 0) && (inheritItemInfo != nullptr))
             weight = inheritItemInfo->getWeight();
         itemInfo->setWeight(weight);
-        if (attackAction.empty() && inheritItemInfo)
+        if (attackAction.empty() && (inheritItemInfo != nullptr))
             attackAction = inheritItemInfo->getAttackAction();
         itemInfo->setAttackAction(attackAction);
-        if (skyAttackAction.empty() && inheritItemInfo)
+        if (skyAttackAction.empty() && (inheritItemInfo != nullptr))
             skyAttackAction = inheritItemInfo->getSkyAttackAction();
         itemInfo->setSkyAttackAction(skyAttackAction);
-        if (waterAttackAction.empty() && inheritItemInfo)
+        if (waterAttackAction.empty() && (inheritItemInfo != nullptr))
             waterAttackAction = inheritItemInfo->getWaterAttackAction();
         itemInfo->setWaterAttackAction(waterAttackAction);
-        if (rideAttackAction.empty() && inheritItemInfo)
+        if (rideAttackAction.empty() && (inheritItemInfo != nullptr))
             rideAttackAction = inheritItemInfo->getRideAttackAction();
         itemInfo->setRideAttackAction(rideAttackAction);
-        if (!attackRange && inheritItemInfo)
+        if ((attackRange == 0) && (inheritItemInfo != nullptr))
             attackRange = inheritItemInfo->getAttackRange();
         itemInfo->setAttackRange(attackRange);
-        if (missileParticle.empty() && inheritItemInfo)
+        if (missileParticle.empty() && (inheritItemInfo != nullptr))
             missileParticle = inheritItemInfo->getMissileParticleFile();
         itemInfo->setMissileParticleFile(missileParticle);
-        if (!hitEffectId && inheritItemInfo)
+        if ((hitEffectId == 0) && (inheritItemInfo != nullptr))
             hitEffectId = inheritItemInfo->getHitEffectId();
         itemInfo->setHitEffectId(hitEffectId);
-        if (!criticalEffectId && inheritItemInfo)
+        if ((criticalEffectId == 0) && (inheritItemInfo != nullptr))
             criticalEffectId = inheritItemInfo->getCriticalHitEffectId();
         itemInfo->setCriticalHitEffectId(criticalEffectId);
-        if (!missEffectId && inheritItemInfo)
+        if ((missEffectId == 0) && (inheritItemInfo != nullptr))
             missEffectId = inheritItemInfo->getMissEffectId();
         itemInfo->setMissEffectId(missEffectId);
         itemInfo->setDrawBefore(-1, parseSpriteName(drawBefore));
         itemInfo->setDrawAfter(-1, parseSpriteName(drawAfter));
         itemInfo->setDrawPriority(-1, drawPriority);
-        if (colors.empty() && inheritItemInfo)
+        if (colors.empty() && (inheritItemInfo != nullptr))
             colors = inheritItemInfo->getColorsListName();
         itemInfo->setColorsList(colors);
-        if (iconColors.empty() && inheritItemInfo)
+        if (iconColors.empty() && (inheritItemInfo != nullptr))
             iconColors = inheritItemInfo->getIconColorsListName();
         itemInfo->setIconColorsList(iconColors);
         itemInfo->setMaxFloorOffsetX(maxFloorOffsetX);
@@ -516,7 +516,7 @@ void ItemDB::loadXmlFile(const std::string &fileName,
         if (!effect.empty() && !temp.empty())
             effect.append(" / ");
         effect.append(temp);
-        if (effect.empty() && inheritItemInfo)
+        if (effect.empty() && (inheritItemInfo != nullptr))
             effect = inheritItemInfo->getEffect();
         itemInfo->setEffect(effect);
 
@@ -840,7 +840,7 @@ static int parseDirectionName(const std::string &name)
 static void loadSpriteRef(ItemInfo *const itemInfo, XmlNodeConstPtr node)
 {
     const std::string gender = XML::getProperty(node, "gender", "unisex");
-    if (!node || !XmlHaveChildContent(node))
+    if ((node == nullptr) || !XmlHaveChildContent(node))
         return;
 
     const std::string filename = XmlChildContent(node);
@@ -856,7 +856,7 @@ static void loadSpriteRef(ItemInfo *const itemInfo, XmlNodeConstPtr node)
 
 static void loadSoundRef(ItemInfo *const itemInfo, XmlNodeConstPtr node)
 {
-    if (!node || !XmlHaveChildContent(node))
+    if ((node == nullptr) || !XmlHaveChildContent(node))
         return;
     const std::string event = XML::getProperty(node, "event", "");
     const std::string filename = XmlChildContent(node);
@@ -878,7 +878,7 @@ static void loadSoundRef(ItemInfo *const itemInfo, XmlNodeConstPtr node)
 static void loadFloorSprite(SpriteDisplay &display,
                             XmlNodeConstPtrConst floorNode)
 {
-    if (!floorNode)
+    if (floorNode == nullptr)
         return;
     for_each_xml_child_node(spriteNode, floorNode)
     {
@@ -902,7 +902,7 @@ static void loadFloorSprite(SpriteDisplay &display,
 static void loadReplaceSprite(ItemInfo *const itemInfo,
                               XmlNodeConstPtr replaceNode)
 {
-    if (!replaceNode)
+    if (replaceNode == nullptr)
         return;
     const std::string removeSprite = XML::getProperty(
         replaceNode, "sprite", "");
@@ -929,7 +929,7 @@ static void loadReplaceSprite(ItemInfo *const itemInfo,
                 {
                     IntMap *const mapList = itemInfo->addReplaceSprite(
                         parseSpriteName(removeSprite), f);
-                    if (!mapList)
+                    if (mapList == nullptr)
                         continue;
                     for_each_xml_child_node(itemNode, replaceNode)
                     {
@@ -963,17 +963,17 @@ static void loadReplaceSprite(ItemInfo *const itemInfo,
                     const int to = XML::getProperty(itemNode, "to", 1);
                     IntMap *mapList = itemInfo->addReplaceSprite(
                         parseSpriteName(removeSprite), SpriteDirection::DOWN);
-                    if (mapList)
+                    if (mapList != nullptr)
                         (*mapList)[from] = to;
 
                     mapList = itemInfo->addReplaceSprite(parseSpriteName(
                         removeSprite), SpriteDirection::DOWNLEFT);
-                    if (mapList)
+                    if (mapList != nullptr)
                         (*mapList)[from] = to;
 
                     mapList = itemInfo->addReplaceSprite(parseSpriteName(
                         removeSprite), SpriteDirection::DOWNRIGHT);
-                    if (mapList)
+                    if (mapList != nullptr)
                         (*mapList)[from] = to;
                 }
             }
@@ -996,17 +996,17 @@ static void loadReplaceSprite(ItemInfo *const itemInfo,
                     const int to = XML::getProperty(itemNode, "to", 1);
                     IntMap *mapList = itemInfo->addReplaceSprite(
                         parseSpriteName(removeSprite), SpriteDirection::UP);
-                    if (mapList)
+                    if (mapList != nullptr)
                         (*mapList)[from] = to;
 
                     mapList = itemInfo->addReplaceSprite(parseSpriteName(
                         removeSprite), SpriteDirection::UPLEFT);
-                    if (mapList)
+                    if (mapList != nullptr)
                         (*mapList)[from] = to;
 
                     mapList = itemInfo->addReplaceSprite(parseSpriteName(
                         removeSprite), SpriteDirection::UPRIGHT);
-                    if (mapList)
+                    if (mapList != nullptr)
                         (*mapList)[from] = to;
                 }
             }
@@ -1016,7 +1016,7 @@ static void loadReplaceSprite(ItemInfo *const itemInfo,
         {
             IntMap *const mapList = itemInfo->addReplaceSprite(
                 parseSpriteName(removeSprite), direction);
-            if (!mapList)
+            if (mapList == nullptr)
                 return;
             for_each_xml_child_node(itemNode, replaceNode)
             {
diff --git a/src/resources/db/itemfielddb.cpp b/src/resources/db/itemfielddb.cpp
index 65020e824..8a32ccc02 100644
--- a/src/resources/db/itemfielddb.cpp
+++ b/src/resources/db/itemfielddb.cpp
@@ -107,7 +107,7 @@ void ItemFieldDb::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "itemfields"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "itemfields"))
     {
         logger->log("ItemFieldDb: Error while loading %s!",
             fileName.c_str());
diff --git a/src/resources/db/itemoptiondb.cpp b/src/resources/db/itemoptiondb.cpp
index 1199e07f7..bd78f95c5 100644
--- a/src/resources/db/itemoptiondb.cpp
+++ b/src/resources/db/itemoptiondb.cpp
@@ -88,7 +88,7 @@ void ItemOptionDb::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "itemoptions"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "itemoptions"))
     {
         if (skipError == SkipError_true)
         {
diff --git a/src/resources/db/languagedb.cpp b/src/resources/db/languagedb.cpp
index b7e3ebc0e..a5443824e 100644
--- a/src/resources/db/languagedb.cpp
+++ b/src/resources/db/languagedb.cpp
@@ -52,7 +52,7 @@ void LanguageDb::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst root = doc->rootNode();
 
-    if (!root || !xmlNameEqual(root, "languages"))
+    if ((root == nullptr) || !xmlNameEqual(root, "languages"))
     {
         delete doc;
         return;
diff --git a/src/resources/db/mapdb.cpp b/src/resources/db/mapdb.cpp
index d991e8273..e96f31e52 100644
--- a/src/resources/db/mapdb.cpp
+++ b/src/resources/db/mapdb.cpp
@@ -67,7 +67,7 @@ void MapDB::loadRemapXmlFile(const std::string &fileName,
         skipError);
 
     XmlNodeConstPtrConst root = doc->rootNode();
-    if (!root)
+    if (root == nullptr)
     {
         delete doc;
         return;
@@ -101,7 +101,7 @@ void MapDB::loadRemapXmlFile(const std::string &fileName,
 
 void MapDB::readMap(XmlNodePtrConst node)
 {
-    if (!node)
+    if (node == nullptr)
         return;
     const std::string map = XML::getProperty(node, "name", "");
     if (map.empty())
@@ -121,7 +121,7 @@ void MapDB::readMap(XmlNodePtrConst node)
 
 void MapDB::readAtlas(XmlNodePtrConst node)
 {
-    if (!node)
+    if (node == nullptr)
         return;
     const std::string atlas = XML::getProperty(node, "name", "");
     if (atlas.empty())
@@ -154,7 +154,7 @@ void MapDB::loadInfo(const std::string &fileName,
         UseVirtFs_true,
         skipError);
     XmlNodeConstPtrConst root = doc->rootNode();
-    if (!root)
+    if (root == nullptr)
     {
         delete doc;
         return;
diff --git a/src/resources/db/mercenarydb.cpp b/src/resources/db/mercenarydb.cpp
index bc1b20840..a528c7def 100644
--- a/src/resources/db/mercenarydb.cpp
+++ b/src/resources/db/mercenarydb.cpp
@@ -60,7 +60,7 @@ void MercenaryDB::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtr rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "mercenaries"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "mercenaries"))
     {
         logger->log("MercenaryDB: Error while loading %s!",
             paths.getStringValue("mercenariesFile").c_str());
@@ -92,7 +92,7 @@ void MercenaryDB::loadXmlFile(const std::string &fileName,
             logger->log("MercenaryDB: Redefinition of mercenary ID %d", id);
             currentInfo = mMercenaryInfos[fromInt(id + offset, BeingTypeId)];
         }
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setBlockType(BlockType::NONE);
@@ -111,7 +111,7 @@ void MercenaryDB::loadXmlFile(const std::string &fileName,
         currentInfo->setColorsList(XML::getProperty(mercenaryNode,
             "colors", ""));
 
-        if (currentInfo->getMaxHP())
+        if (currentInfo->getMaxHP() != 0)
             currentInfo->setStaticMaxHP(true);
 
         SpriteDisplay display;
diff --git a/src/resources/db/moddb.cpp b/src/resources/db/moddb.cpp
index 7a23e255f..5932d9b19 100644
--- a/src/resources/db/moddb.cpp
+++ b/src/resources/db/moddb.cpp
@@ -54,7 +54,7 @@ void ModDB::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "mods"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "mods"))
     {
         logger->log("Mods Database: Error while loading %s!",
             fileName.c_str());
@@ -80,7 +80,7 @@ void ModDB::loadXmlFile(const std::string &fileName,
         ModInfo *currentInfo = nullptr;
         if (mModInfos.find(name) != mModInfos.end())
             currentInfo = mModInfos[name];
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new ModInfo;
 
         currentInfo->setName(name);
diff --git a/src/resources/db/monsterdb.cpp b/src/resources/db/monsterdb.cpp
index 1ed0caa27..44b430144 100644
--- a/src/resources/db/monsterdb.cpp
+++ b/src/resources/db/monsterdb.cpp
@@ -62,7 +62,7 @@ void MonsterDB::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtr rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "monsters"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "monsters"))
     {
         logger->log("Monster Database: Error while loading %s!",
             paths.getStringValue("monstersFile").c_str());
@@ -94,7 +94,7 @@ void MonsterDB::loadXmlFile(const std::string &fileName,
             logger->log("MonsterDB: Redefinition of monster ID %d", id);
             currentInfo = mMonsterInfos[fromInt(id + offset, BeingTypeId)];
         }
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setBlockType(BlockType::NONE);
@@ -114,7 +114,7 @@ void MonsterDB::loadXmlFile(const std::string &fileName,
         currentInfo->setColorsList(XML::getProperty(monsterNode,
             "colors", ""));
 
-        if (currentInfo->getMaxHP())
+        if (currentInfo->getMaxHP() != 0)
             currentInfo->setStaticMaxHP(true);
 
         SpriteDisplay display;
diff --git a/src/resources/db/npcdb.cpp b/src/resources/db/npcdb.cpp
index 9be217819..44a0bc747 100644
--- a/src/resources/db/npcdb.cpp
+++ b/src/resources/db/npcdb.cpp
@@ -63,7 +63,7 @@ void NPCDB::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "npcs"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "npcs"))
     {
         logger->log("NPC Database: Error while loading %s!",
             paths.getStringValue("npcsFile").c_str());
@@ -99,7 +99,7 @@ void NPCDB::loadXmlFile(const std::string &fileName,
             logger->log("NpcDB: Redefinition of npc ID %d", toInt(id, int));
             currentInfo = mNPCInfos[id];
         }
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setTargetSelection(XML::getBoolProperty(npcNode,
@@ -198,7 +198,7 @@ BeingInfo *NPCDB::get(const BeingTypeId id)
 BeingTypeId NPCDB::getAvatarFor(const BeingTypeId id)
 {
     const BeingInfo *const info = get(id);
-    if (!info)
+    if (info == nullptr)
         return BeingTypeId_zero;
     return info->getAvatarId();
 }
diff --git a/src/resources/db/npcdialogdb.cpp b/src/resources/db/npcdialogdb.cpp
index 76eaea7c5..7411faca9 100644
--- a/src/resources/db/npcdialogdb.cpp
+++ b/src/resources/db/npcdialogdb.cpp
@@ -155,7 +155,7 @@ void NpcDialogDB::loadXmlFile(const std::string &fileName,
         skipError);
 
     XmlNodeConstPtrConst root = doc->rootNode();
-    if (!root)
+    if (root == nullptr)
     {
         delete doc;
         return;
diff --git a/src/resources/db/petdb.cpp b/src/resources/db/petdb.cpp
index 5dca543a0..a47956e7f 100644
--- a/src/resources/db/petdb.cpp
+++ b/src/resources/db/petdb.cpp
@@ -61,7 +61,7 @@ void PETDB::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "pets"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "pets"))
     {
         logger->log("PET Database: Error while loading %s!",
             fileName.c_str());
@@ -95,7 +95,7 @@ void PETDB::loadXmlFile(const std::string &fileName,
         BeingInfo *currentInfo = nullptr;
         if (mPETInfos.find(id) != mPETInfos.end())
             currentInfo = mPETInfos[id];
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setName(XML::langProperty(petNode,
diff --git a/src/resources/db/questdb.cpp b/src/resources/db/questdb.cpp
index 41b3b0062..db67e5138 100644
--- a/src/resources/db/questdb.cpp
+++ b/src/resources/db/questdb.cpp
@@ -54,7 +54,7 @@ void QuestDb::load()
 static void loadQuest(const int var,
                       XmlNodeConstPtr node)
 {
-    if (!node)
+    if (node == nullptr)
         return;
     QuestItem *const quest = new QuestItem;
     // TRANSLATORS: quests window quest name
@@ -85,7 +85,7 @@ static void loadQuest(const int var,
             continue;
         XmlChar *const data = reinterpret_cast<XmlChar*>(
             XmlNodeGetContent(dataNode));
-        if (!data)
+        if (data == nullptr)
             continue;
         std::string str = translator->getStr(data);
         XmlFree(data);
@@ -181,7 +181,7 @@ void QuestDb::loadXmlFile(const std::string &fileName,
         UseVirtFs_true,
         skipError);
     XmlNodeConstPtrConst root = doc.rootNode();
-    if (!root)
+    if (root == nullptr)
         return;
 
     for_each_xml_child_node(varNode, root)
diff --git a/src/resources/db/skillunitdb.cpp b/src/resources/db/skillunitdb.cpp
index cec48a4a1..b5c4592ad 100644
--- a/src/resources/db/skillunitdb.cpp
+++ b/src/resources/db/skillunitdb.cpp
@@ -59,7 +59,7 @@ void SkillUnitDb::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "skillunits"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "skillunits"))
     {
         logger->log("SkillUnitDb: Error while loading %s!",
             fileName.c_str());
@@ -94,7 +94,7 @@ void SkillUnitDb::loadXmlFile(const std::string &fileName,
         BeingInfo *currentInfo = nullptr;
         if (mSkillUnitInfos.find(id) != mSkillUnitInfos.end())
             currentInfo = mSkillUnitInfos[id];
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setName(XML::langProperty(skillUnitNode,
diff --git a/src/resources/db/sounddb.cpp b/src/resources/db/sounddb.cpp
index d58a585ee..47eb99232 100644
--- a/src/resources/db/sounddb.cpp
+++ b/src/resources/db/sounddb.cpp
@@ -51,7 +51,7 @@ void SoundDB::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst root = doc->rootNode();
 
-    if (!root || !xmlNameEqual(root, "sounds"))
+    if ((root == nullptr) || !xmlNameEqual(root, "sounds"))
     {
         delete doc;
         return;
@@ -70,7 +70,7 @@ void SoundDB::loadXmlFile(const std::string &fileName,
         {
             const std::string name = XML::getProperty(node, "name", "");
             const int id = NotifyManager::getIndexBySound(name);
-            if (id)
+            if (id != 0)
             {
                 const std::string value = XML::getProperty(node, "value", "");
                 mSounds[id] = value;
diff --git a/src/resources/db/statdb.cpp b/src/resources/db/statdb.cpp
index 12126f36a..7911009a3 100644
--- a/src/resources/db/statdb.cpp
+++ b/src/resources/db/statdb.cpp
@@ -175,7 +175,7 @@ void StatDb::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "stats"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "stats"))
     {
         logger->log("StatDb: Error while loading %s!",
             fileName.c_str());
diff --git a/src/resources/db/statuseffectdb.cpp b/src/resources/db/statuseffectdb.cpp
index 58c5cf30d..d5fc96849 100644
--- a/src/resources/db/statuseffectdb.cpp
+++ b/src/resources/db/statuseffectdb.cpp
@@ -90,7 +90,7 @@ void StatusEffectDB::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "status-effects"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "status-effects"))
     {
         logger->log("Error loading status effects file: " + fileName);
         return;
@@ -151,9 +151,9 @@ void StatusEffectDB::loadXmlFile(const std::string &fileName,
         StatusEffect *endEffect = statusEffects[0][id];
         const std::string name = XML::getProperty(node, "name", "");
         const std::string name2 = XML::langProperty(node, "name", "");
-        if (!startEffect)
+        if (startEffect == nullptr)
             startEffect = new StatusEffect;
-        if (!endEffect)
+        if (endEffect == nullptr)
             endEffect = new StatusEffect;
 
         startEffect->mName = name2;
diff --git a/src/resources/db/textdb.cpp b/src/resources/db/textdb.cpp
index 24a5f2a38..e4d0b9b65 100644
--- a/src/resources/db/textdb.cpp
+++ b/src/resources/db/textdb.cpp
@@ -49,7 +49,7 @@ void TextDb::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst root = doc->rootNode();
 
-    if (!root || !xmlNameEqual(root, "texts"))
+    if ((root == nullptr) || !xmlNameEqual(root, "texts"))
     {
         delete doc;
         return;
diff --git a/src/resources/db/unitsdb.cpp b/src/resources/db/unitsdb.cpp
index 0437c81e4..9481406c4 100644
--- a/src/resources/db/unitsdb.cpp
+++ b/src/resources/db/unitsdb.cpp
@@ -193,7 +193,7 @@ void UnitsDb::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtrConst root = doc.rootNode();
 
-    if (!root || !xmlNameEqual(root, "units"))
+    if ((root == nullptr) || !xmlNameEqual(root, "units"))
     {
         logger->log("Error loading unit definition file: "
             + paths.getStringValue("unitsFile"));
@@ -259,7 +259,7 @@ static std::string formatUnit(const int value,
             int levelAmount = CAST_S32(amount);
             int nextAmount = 0;
 
-            if (ul.count)
+            if (ul.count != 0)
                 levelAmount /= ul.count;
 
             amount -= static_cast<double>(levelAmount * ul.count);
@@ -275,7 +275,7 @@ static std::string formatUnit(const int value,
                 pl = ul;
                 ul = ud.levels[i];
 
-                if (ul.count)
+                if (ul.count != 0)
                 {
                     nextAmount = levelAmount / ul.count;
                     levelAmount %= ul.count;
@@ -287,7 +287,7 @@ static std::string formatUnit(const int value,
                         pl.separator).append(pl.symbol).append(output);
                 }
 
-                if (!nextAmount)
+                if (nextAmount == 0)
                     break;
                 levelAmount = nextAmount;
             }
@@ -305,7 +305,7 @@ static std::string formatUnit(const int value,
                     ul = ud.levels[i - 1];
                     break;
                 }
-                if (ul.count)
+                if (ul.count != 0)
                     amount /= ul.count;
             }